Batrider really is in need of a cleanup for his ability descriptions. They partially contain wrong information and can be misleading.

Current issues:

1. Sticky Napalm does not mention its damage type. It's missing "AbilityUnitDamageType" "DAMAGE_TYPE_MAGICAL" in the npc_abilities.txt
2. Sticky Napalm description says that it drenches an area in oil, and not enemy units within the area. So it sounds like you have to stay within the area to be affected.
3. Sticky Napalm description only says that the damage scales with stacks. The scaling slow is not mentioned.
4. Sticky Napalm's single ALT note is slightly outdated, only mentions Orb Of Venom and Radiance, doesn't mention Urn of Shadows and Blade Mail
5. Sticky Napalm traits could be reworded to be clear that they are per-stack. It currently only says "extra damage" and "movement slow"
6. Flamebreak doesn't tell its knockback distance (it is not equal to the explosion radius, so it should be mentioned)
7. Flamebreak's debuff says it deals 50 damage per second. Wrong value. It dealt 50 dps as the instance damage was changed to a dps. Now it deals damage scaling with ability level.
8. Flaming Lasso does not mention its damage type. It's missing "AbilityUnitDamageType" "DAMAGE_TYPE_MAGICAL" in the npc_abilities.txt
9. Flaming Lasso description says that it cannot drag units over impassable terrain. This is simply not true. That sentence needs to be removed.
10. Flaming Lasso's self-disarm should be in the main ability description. It should not be hidden in the ALT notes. It's a significant aspect of the spell, and not just some interaction which doesn't special mention.


Other stuff which could be added/improved, mainly ALT notes:

Sticky Napalm:
1. Remove the max stack part from Sticky Napalm's description and add it to the traits below instead
2. Reword the damge trait from "extra damage" to "hero damage per stack", and also add "creep damage per stack" below it
3. Reword the slow trait from "movement slow" to "movement slow per stack"
4. Add ALT note: The turn rate slow is always the same, regardless of amount of stacks
5. Add ALT note: Adding a new stack refreshes the entire stack on an enemy
6. Add ALT note: Its damage is dealt in a separate instance

Flamebreak:
1. Add ALT note: Projectile speed (900)
2. Add ALT note: The knockback distance is dynamic, based on the proximity to the center
3. Add ALT note: Enemies are not disabled during the knockback
4. Add ALT note: Does not affect Roshan
5. Add knockback distance and duration to the traits

Firefly:
1. Change "the Batrider" to just "Batrider" in the already existing ALT notes
2. Add ALT note: The entire path disappears at once upon the spell expiring
3. Add ALT note: Multiple instances of Firefly fully stack
4. Add ALT note: Does not affect Roshan

Flaming Lasso:
1. Change "the Batrider" to just "Batrider" in the already existing ALT notes
2. Reword the Aghanim's Scepter text to be shorter and more compact. It's unnecessarily long. Also, it shouldn't mention any direct numbers, since these are usually forgotten when the values get changed in a patch
3. Reword the already existing ALT note about the lasso ending on Bat or target death for readability
4. The value in the second ALT note about the Lasso break distance is wrong. It's 425, not 400
5. Remove unnecessary ALT note about it disabling through spell immunity. The info is already in the header
6. Add ALT note: The target is dragged 300 range behind Batrider, and the aghs target 300 range behind primary target
7. Add ALT note: Deals damage in 0.5 second intervals

Image comparing the changes to the current tooltips
Spoiler: 



Here are the modified sections of dota_english.txt and npc_abilities.txt required for these changes and additions. Changed values are marked red and new values are marked blue.


Code:
		//BATRIDER
		"DOTA_Tooltip_ability_batrider_sticky_napalm"						"Sticky Napalm"
		"DOTA_Tooltip_ability_batrider_sticky_napalm_Description"			"Drenches enemies within an area in sticky oil, amplifying damage from Batrider's attacks and abilities and slowing their movement speed and turn rate. Additional casts of Sticky Napalm continue to increase damage and movement speed slow."
		"DOTA_Tooltip_ability_batrider_sticky_napalm_Lore"					"It's not uncommon to hear the Rider cackle while he increases the flammability of his opponents."
		"DOTA_Tooltip_ability_batrider_sticky_napalm_Note0"					"One stack is enough to apply the full turn rate slow."
		"DOTA_Tooltip_ability_batrider_sticky_napalm_Note1"					"All damage from Batrider gets amplified, except for Radiance, Orb of Venom, Urn of Shadows and Blade Mail."
		"DOTA_Tooltip_ability_batrider_sticky_napalm_Note2"					"The entire stack gets refreshed whenever a new stack is added."
		"DOTA_Tooltip_ability_batrider_sticky_napalm_Note3"					"Sticky Napalm deals its damage in a separate instance."
		"DOTA_Tooltip_ability_batrider_sticky_napalm_damage"				"HERO DAMAGE PER STACK:"
		"DOTA_Tooltip_ability_batrider_sticky_napalm_damage_creep"			"CREEP DAMAGE PER STACK:"
		"DOTA_Tooltip_ability_batrider_sticky_napalm_max_stacks"			"MAX STACKS:"
		"DOTA_Tooltip_ability_batrider_sticky_napalm_duration"				"DURATION:"
		"DOTA_Tooltip_ability_batrider_sticky_napalm_movement_speed_pct"	"%MOVEMENT SLOW PER STACK:"
		"DOTA_Tooltip_ability_batrider_sticky_napalm_turn_rate_pct"			"%TURN RATE SLOW:"
		"DOTA_Tooltip_ability_batrider_sticky_napalm_radius"				"RADIUS:"
		"DOTA_Tooltip_ability_batrider_flamebreak"							"Flamebreak"
		"DOTA_Tooltip_ability_batrider_flamebreak_Description"				"Hurls an explosive cocktail that explodes when it reaches the target location, knocking back, and dealing damage over time to enemies in the area."
		"DOTA_Tooltip_ability_batrider_flamebreak_Lore"						"A molotov cocktail is the weapon of choice for Batrider."
		"DOTA_Tooltip_ability_batrider_flamebreak_Note0"					"The projectile travels at a speed of 900."
		"DOTA_Tooltip_ability_batrider_flamebreak_Note1"					"The knockback distance is based on the proximity to the explosion center."
		"DOTA_Tooltip_ability_batrider_flamebreak_Note2"					"Enemies are not disabled during the knockback."
		"DOTA_Tooltip_ability_batrider_flamebreak_Note3"					"Does not affect Roshan."
		"DOTA_Tooltip_ability_batrider_flamebreak_damage_per_second"		"DAMAGE PER SECOND:"
		"DOTA_Tooltip_ability_batrider_flamebreak_damage_duration"			"BURN DURATION:"	
		"DOTA_Tooltip_ability_batrider_flamebreak_knockback_duration"		"KNOCKBACK DURATION:"
		"DOTA_Tooltip_ability_batrider_flamebreak_explosion_radius"			"RADIUS:"
		"DOTA_Tooltip_ability_batrider_flamebreak_knockback_max_distance"	"KNOCKBACK DISTANCE:"
		"DOTA_Tooltip_ability_batrider_firefly"								"Firefly"
		"DOTA_Tooltip_ability_batrider_firefly_Description"					"Batrider takes to the skies, laying down a trail of flames from the air. The fire damages any enemies it touches, and destroys trees below Batrider. While flying, Batrider gains unobstructed movement and vision."
		"DOTA_Tooltip_ability_batrider_firefly_Lore"						"When an enemy escapes into the Yama Raskav Jungle, most would cut through the brush to find the fugitive. Batrider just chooses to destroy the jungle along with his foes."
		"DOTA_Tooltip_ability_batrider_firefly_Note0"						"During Firefly, Batrider can fly above units, trees and impassable terrain."
		"DOTA_Tooltip_ability_batrider_firefly_Note1"						"If duration ends when above impassable terrain, Batrider can get stuck."
		"DOTA_Tooltip_ability_batrider_firefly_Note2"						"The trail persists through Batrider's death."
		"DOTA_Tooltip_ability_batrider_firefly_Note3"						"The entire trail disappears at once upon expiring."
		"DOTA_Tooltip_ability_batrider_firefly_Note4"						"Multiple casts of Firefly fully stack."
		"DOTA_Tooltip_ability_batrider_firefly_Note5"						"Does not affect Roshan."
		"DOTA_Tooltip_ability_batrider_firefly_damage_per_second"			"DAMAGE PER SECOND:"
		"DOTA_Tooltip_ability_batrider_firefly_radius"						"RADIUS:"
		"DOTA_Tooltip_ability_batrider_firefly_duration"					"DURATION:"
		"DOTA_Tooltip_ability_batrider_flaming_lasso"						"Flaming Lasso"
		"DOTA_Tooltip_ability_batrider_flaming_lasso_Description"			"Lassoes an enemy and drags them in Batrider's wake. Dragged units cannot move, attack, or use abilities. Teleporting or blinking too far will break the lasso. Batrider cannot attack while having an enemy lassoed.\n\nUpgradable by Aghanim's Scepter."
		"DOTA_Tooltip_ability_batrider_flaming_lasso_aghanim_description"	"Makes Flaming Lasso grab a secondary target near the primary target. The secondary target is tethered to the first. Also causes Flaming Lasso to deal damage over time."
		"DOTA_Tooltip_ability_batrider_flaming_lasso_Lore"					"Few dare to ask to ride on the bat, as Batrider gives them free of charge."
		"DOTA_Tooltip_ability_batrider_flaming_lasso_Note0"					"Flaming Lasso ends immediately when Batrider or the target die."
		"DOTA_Tooltip_ability_batrider_flaming_lasso_Note1"					"If Batrider blinks or teleports more than 425 units away, the lasso breaks."
		"DOTA_Tooltip_ability_batrider_flaming_lasso_Note2"					"Drags the target 300 range behind Batrider, and the secondary target 300 range behind the primary target."
		"DOTA_Tooltip_ability_batrider_flaming_lasso_Note3"					"Deals damage in 0.5 second intervals. The damage hits both targets."
		"DOTA_Tooltip_ability_batrider_flaming_lasso_duration"				"DURATION:"
		"DOTA_Tooltip_ability_batrider_flaming_lasso_damage_scepter"		"SCEPTER DAMAGE PER SECOND:"
		"DOTA_Tooltip_ability_batrider_flaming_lasso_grab_radius_scepter"	"SCEPTER TETHER RANGE:"
		"npc_dota_hero_batrider_bio"										"There is no such thing as harmony among the creatures of the Yama Raskav Jungle. By bite, or claw, or pincer, or hoof, even the slightest sign of weakness means a swift death. They say the Rider was just a lad cutting chaff in his family's field when he was taken, swept up by a massive morde-bat looking for take-out. But this boy had a better idea, and wriggled his way from his captor's grip, onto the beast's back, and hacked it down with his tools. Emerging from the bloody wreckage and intoxicated by the thrill of flight, the boy realized he'd found his calling.  The boy grew, and every summer he'd return to his family's field, often setting out into the bush seeking to reclaim that first thrill of facing death in the form of jaws or a fatal fall. The years went on, but his fire only grew stronger. He studied the overgrowth, plunging deeper with each expedition, until finally he found his way to the caves at the heart of hostility. They say the Rider, on the eve of a scorching summer night, had nothing but a rope, a bottle of liquid courage and a burning determination to feel the skies once more, when he plunged inside..."

		"DOTA_Tooltip_modifier_batrider_sticky_napalm"					"Sticky Napalm"
		"DOTA_Tooltip_modifier_batrider_sticky_napalm_Description"		"Increasing napalm-caster's damage by %dMODIFIER_PROPERTY_TOOLTIP%.\nSlowing turn rate by %dMODIFIER_PROPERTY_TURN_RATE_PERCENTAGE%%%.\nSlowing movement speed by %dMODIFIER_PROPERTY_MOVESPEED_BONUS_PERCENTAGE%%%."
		"DOTA_Tooltip_modifier_flamebreak_damage"						"Flamebreak Burn"
		"DOTA_Tooltip_modifier_flamebreak_damage_Description"			"On fire! Taking damage per second."
		"DOTA_Tooltip_modifier_batrider_firefly"						"Firefly"
		"DOTA_Tooltip_modifier_batrider_firefly_Description"			"Flying and laying down fiery destruction in your wake."
		"DOTA_Tooltip_modifier_batrider_flaming_lasso"					"Flaming Lasso"
		"DOTA_Tooltip_modifier_batrider_flaming_lasso_Description"		"Caught in a Flaming Lasso."
		"DOTA_Tooltip_modifier_batrider_flaming_lasso_self"				"Flaming Lasso Disarm"
		"DOTA_Tooltip_modifier_batrider_flaming_lasso_self_Description"	"Cannot attack while Lasso is active."
Code:
	//=================================================================================================================
	// Batrider: Sticky Napalm
	//=================================================================================================================
	"batrider_sticky_napalm"
	{
		// General
		//-------------------------------------------------------------------------------------------------------------
		"ID"					"5320"														// unique ID number for this ability.  Do not change this once established or it will invalidate collected stats.
		"AbilityBehavior"				"DOTA_ABILITY_BEHAVIOR_AOE | DOTA_ABILITY_BEHAVIOR_POINT | DOTA_ABILITY_BEHAVIOR_IGNORE_BACKSWING"
		"SpellImmunityType"				"SPELL_IMMUNITY_ENEMIES_NO"
		"SpellDispellableType"			"SPELL_DISPELLABLE_YES"
		"AbilityUnitDamageType"			"DAMAGE_TYPE_MAGICAL"
		
		// Casting
		//-------------------------------------------------------------------------------------------------------------
		"AbilityCastRange"				"700"
		"AbilityCastPoint"				"0.2 0.2 0.2 0.2"

		// Time		
		//-------------------------------------------------------------------------------------------------------------
		"AbilityCooldown"				"3.0 3.0 3.0 3.0"

		// Cost
		//-------------------------------------------------------------------------------------------------------------
		"AbilityManaCost"				"20 20 20 20"

		// Stats
		//-------------------------------------------------------------------------------------------------------------
		"AbilityModifierSupportValue"	"0.5"	// Works by boosting damage


		// Special
		//-------------------------------------------------------------------------------------------------------------
		"AbilitySpecial"
		{
			"01"
			{
				"var_type"				"FIELD_INTEGER"
				"damage"				"10 15 20 25"
			}
			"02"
			{
				"var_type"				"FIELD_INTEGER"
				"damage_creep"				"5 7.5 10 12.5"
			}
			"03"
			{
				"var_type"				"FIELD_INTEGER"
				"radius"				"375 375 375 375"
			}
			"04"
			{
				"var_type"				"FIELD_FLOAT"
				"duration"				"8.0 8.0 8.0 8.0"
			}
			"05"
			{
				"var_type"				"FIELD_INTEGER"
				"movement_speed_pct"	"-3 -5 -7 -9"
			}
			"06"
			{
				"var_type"				"FIELD_INTEGER"
				"turn_rate_pct"			"-70 -70 -70 -70"
			}
			"07"
			{
				"var_type"				"FIELD_INTEGER"
				"max_stacks"			"10 10 10 10"
			}
		}
	}


	//=================================================================================================================
	// Batrider: Flaming Lasso
	//=================================================================================================================
	"batrider_flaming_lasso"
	{
		// General
		//-------------------------------------------------------------------------------------------------------------
		"ID"					"5323"														// unique ID number for this ability.  Do not change this once established or it will invalidate collected stats.
		"AbilityBehavior"				"DOTA_ABILITY_BEHAVIOR_UNIT_TARGET"
		"AbilityUnitTargetTeam"			"DOTA_UNIT_TARGET_TEAM_ENEMY"
		"AbilityUnitTargetType"			"DOTA_UNIT_TARGET_HERO | DOTA_UNIT_TARGET_BASIC"
		"AbilityUnitTargetFlags"		"DOTA_UNIT_TARGET_FLAG_MAGIC_IMMUNE_ENEMIES"
		"SpellImmunityType"				"SPELL_IMMUNITY_ENEMIES_YES"
		"SpellDispellableType"			"SPELL_DISPELLABLE_YES_STRONG"
		"AbilityUnitDamageType"			"DAMAGE_TYPE_MAGICAL"
		"AbilityType"					"DOTA_ABILITY_TYPE_ULTIMATE"
		"FightRecapLevel"				"2"

		"HasScepterUpgrade"			"1"
		
		// Casting
		//-------------------------------------------------------------------------------------------------------------
		"AbilityCastPoint"				"0.2 0.2 0.2 0.2"

		// Time		
		//-------------------------------------------------------------------------------------------------------------
		"AbilityCastRange"				"100"
		"AbilityCooldown"				"90.0 75.0 60.0"

		// Cost
		//-------------------------------------------------------------------------------------------------------------
		"AbilityManaCost"				"225"

		// Special
		//-------------------------------------------------------------------------------------------------------------
		"AbilitySpecial"
		{
			"01"
			{
				"var_type"				"FIELD_FLOAT"
				"duration"				"3.0 3.5 4.0"
			}
			"02"
			{
				"var_type"				"FIELD_INTEGER"
				"drag_distance"			"300 300 300"
			}
			"03"
			{
				"var_type"				"FIELD_INTEGER"
				"break_distance"		"425"
			}
			"04"
			{
				"var_type"				"FIELD_INTEGER"
				"grab_radius"		"400"
			}
			"05"
			{
				"var_type"				"FIELD_INTEGER"
				"grab_radius_scepter"		"400"
			}
			"06"
			{
				"var_type"				"FIELD_FLOAT"
				"damage_scepter"		"100"
			}
		}
	}