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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds genuinely new behavior context: this is a polling endpoint and the job may still be in flight. The only blemish is referencing poll_after_seconds, which does not exist in the input schema, so an agent may briefly look for a parameter that isn't there.

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?

Two short sentences, front-loaded with the primary action and immediately followed by the routing condition and the polling instruction. No filler words or repetition of the title.

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 one-parameter read tool with full annotation coverage, the description supplies what matters: when the job is still running and what to do next. There is no output schema, and the return shape (status values, loop/track fields) is only hinted at, which is the one remaining gap.

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 coverage is 100% with a single required 'id' parameter, so the baseline is 3. The description restates that the id identifies the job but adds no format or source detail beyond the schema, which already says where the id comes from.

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 uses a specific verb and resource ("Check a generate_music job by id") and explicitly frames this as the status-check counterpart to generate_music, so it is distinguishable from all siblings 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?

It states the exact condition that selects this tool ("only when it came back status 'running'") and names the alternative behavior (most calls finish inside generate_music), plus the polling loop until the track is ready. This is explicit when-to-use and when-not guidance.

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