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

Annotations already cover the safety profile (readOnlyHint, destructiveHint=false, openWorldHint=false), so the bar is lower. The description nonetheless adds real behavior: the project scoping constraint, that the result carries the project identity, and an explicit refusal path when no track was supplied — none of which the annotations convey. It does not explain pagination or result granularity, keeping it out of 5 territory.

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?

Front-loads the two operative labels (PROJECT-SCOPED, READ) so the agent can triage scope and operation type immediately. Dense but each clause carries information; the em-dash enumeration is long yet specific. No filler sentences.

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?

For a read-only analysis tool with no output schema, the description takes on the return-value burden and does so by enumerating the structural elements returned with program positions. Safety is covered by annotations and the refusal rule is stated. The remaining hole is music_id semantics, which is left entirely unexplained.

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?

With 50% schema coverage, the description needs to compensate. It reinforces the project_id scope ('acts only on the explicit project_id'), which the schema already documents, but the second parameter music_id is undocumented in both the schema and the description — an agent gets no guidance on when or how to supply it. Partial compensation only.

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 — 'READ: the structure of the user's track' — and enumerates the returned elements (tempo, beats, bars, sections, drops, gaps, drum hits, 808s, filter openings). This is far more than a tautology. It does not, however, explicitly differentiate itself from sibling get_audio_analysis, which an agent would plausibly confuse it with.

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?

'Refuses when the user supplied no track (never choose music; the speech prosody grid is the clock then)' gives a concrete when-not condition and names the fallback clock instead of leaving the agent to guess. It stops short of pointing at the actual sibling tool (e.g. get_audio_analysis) to call when a track does exist, so it is clear context with an exclusion rather than full alternative routing.

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