list_music

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

Annotations already declare this a safe read (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is low, and the description still adds real behavior: new downloads from the Epidemic Sound source folder are copied in first, and playback only ever plays the single file, never a song beside it. The ffmpeg mixing instruction is genuinely useful invocation context, though the phrasing around it is muddled.

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?

Purpose and usage are front-loaded, but the body drifts into tangential material — the explanation of what SFX are (whoosh, pop, typing) and the ffmpeg mixing/voice-over passage read as production coaching rather than tool definition. Trimming those would sharpen an otherwise efficient opening.

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?

There is no output schema, and the description compensates by enumerating the exact fields returned and the side effect of importing new downloads. Combined with the two optional filters, an agent has enough to call it and interpret results, though it never says whether an empty library or no-match query returns an empty list.

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 100%, so the schema already documents both `group` (Music or SFX, omit for all) and `query` (words in the file name). The description adds the field list returned but no extra semantics for the parameters themselves, so the baseline 3 applies.

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 and resource (list the user's music and sound effects) and enumerates the returned fields (file, title, artist, genre, bpm, duration, path), which no sibling like list_broll or search_media claims. An agent can tell it apart from the other library/media tools without opening a schema.

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?

"Use for picking a song or an SFX for an edit" plus "The app's Use button asks you for this" give clear triggering conditions. It stops short of naming alternatives (e.g. search_media for cross-library lookups, get_library for general assets), so there is no explicit exclusion guidance.

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