timeline_add_track

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden. It does disclose meaningful behavior: appending creates a new track, track_name auto-generates when omitted, and booleans set initial muted/hidden/locked states. However, it does not mention name-uniqueness constraints, what happens to existing tracks, or any error conditions.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Leads with a clear one-sentence purpose followed by a compact, single-line-per-parameter argument list. The description is short, scannable, and contains no filler or repetition of the schema's default values.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

All five parameters are covered, the purpose is clear, and an output schema exists so the return value need not be described. The only minor gaps are edge cases like invalid track_type values or naming conflicts, which are not essential for a basic append operation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description fully compensates. Every parameter is given practical meaning: track_type is restricted to 'video' or 'audio', track_name is optional and auto-generated, and mute/hide/locked are described by their start-state effects. This is far more valuable than the bare schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb ('Append'), a specific resource ('video or audio track'), and the destination ('to the timeline'). This clearly distinguishes it from sibling tools like timeline_add_clip, track_set_muted, and timeline_remove_track.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides no guidance on when to choose this tool over alternatives, no exclusions, and no context about prerequisites such as having a timeline open. An agent must infer usage purely from the generic 'Append a video or audio track' statement.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.