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

With no annotations, the description carries the full behavioral burden and does so well: it discloses that non-existent album/track numbers return an empty versions[] rather than an error, that cutdown rows lack track_bpm and the four dimension tags (inherited from the main track), that libraryType is not returned by this endpoint itself, and that track_url is audition-only. These are non-obvious behaviors an agent could not infer from the schema.

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?

The text is well front-loaded and organized with clear section markers (When / Args / Returns), and the critical constraint about km_search being blind to cutdowns appears early with a warning glyph. The cost is that every statement is duplicated in Chinese and English, roughly doubling length without adding information for a bilingual reader.

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?

With no output schema, the description fully documents the return shape ({ albumCode, trackNumber, total, versions[] }), the sort order (longest to shortest), the per-version fields to inspect (track_version, track_duration, orginal_time, track_mixout), and explicitly flags which fields are absent from cutdown rows. Nothing an agent needs to interpret the response is missing.

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 all three parameters are already documented in the schema, including the instruction to use the MAIN track's track_number. The description largely restates this, adding only the sourcing note that both required values come from the km_search track object, which is already implied by the schema. Baseline 3 is correct when the schema does the heavy lifting.

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?

The description gives a specific verb+resource ('Lists every cutdown version of one track') and enumerates the concrete version set (Full Length / 60 Sec / 30 Sec / 20 Sec / 15 Sec), so the agent knows exactly what comes back. It also explicitly positions itself against the sibling km_search, stating that km_search only indexes main tracks and cutdowns can ONLY be fetched here.

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?

There is an explicit 'When' section: for ads, TVCs and trailers with hard duration requirements, query this for every track before delivering candidates, because an existing 60s/30s/15s version saves the client an edit. It names the alternative (km_search) and states the precise condition under which that alternative fails, leaving nothing to inference.

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