set_time_signature

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

With no annotations, the description carries the full burden. It explicitly discloses that the tool reports the limitation rather than silently dropping the request, and explains the underlying reason (popover can't be filled via Remote Control API). This goes beyond what annotations would provide.

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 description is a short paragraph with three sentences covering purpose, rationale, and parameter examples. Each sentence earns its place, and the overall length is appropriate for the tool's simplicity.

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?

As a stub that reports an unsupported operation, the description fully explains what the tool does, why it does it, and what the parameter should look like. With an output schema present, return value details are not needed here.

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?

The schema has one parameter, signature, with 0% description coverage. The description adds meaning by providing examples ('4/4', '3/4', '6/8') and indicating the expected format, which the schema does not.

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 clearly states the tool's intended action ('Set a time signature') but immediately clarifies it is 'NOT yet supported over the API' and that the tool actually 'reports the limitation.' This specific behavior distinguishes it from sibling tools like set_key_signature, which presumably works.

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?

The description implies the tool should not be used for actually setting a time signature because the API can't transmit the value, but it gives no explicit 'when to use' or alternative tools. The limitation is clear, but no exclusions or alternatives are mentioned.

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