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

Annotations already declare idempotentHint=true, destructiveHint=false and openWorldHint=false, so the repetition and no-external-fetch statements add limited new information. What does add value beyond annotations is the conflict behavior: 'different current audio refuses replacement', which tells the agent what happens on mismatch rather than silently overwriting. No permissions or cost disclosure, so not a 5.

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?

Three sentences, front-loaded with the action and constraint, then return values, then exclusions. Dense but each sentence carries distinct content (mechanism, return shape, conflict behavior, scope limits). The opening sentence is slightly overloaded with mechanism detail ('durable upload/analysis path').

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?

An output schema exists, yet the description still summarizes the return (attachment/asset/job IDs or already_attached), which is useful for a reuse tool where success is ambiguous. Combined with the empty-target precondition, the mismatch refusal behavior and the scope exclusions, an agent has enough to call this correctly. Auth requirements are the only notable omission.

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 with their provenance (studio_projects_list, studio_song_status). The description adds only that sourceAttachmentId identifies the saved song attachment, which the schema essentially already says, so baseline 3 is appropriate.

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 states a specific verb+resource+mechanism: attaching existing customer audio from a source project to an empty target via the durable upload/analysis path. It is clearly distinguishable from generic attach tools by the 'reuse' framing and the empty-target constraint. It never names the closest sibling (studio_song_attach), so sibling differentiation is implied rather than explicit.

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?

It gives usable preconditions (target must be empty, source must be an accessible project already holding the song) and an explicit scope exclusion: 'No arbitrary URL fetch, generated audio or language-model call', which steers the agent away from import/generation tools. However, it does not name the alternatives the agent should use instead, so routing is left partly to inference.

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