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

Beyond the readOnly/idempotent annotations, it discloses the return shape (start/end in seconds and h:mm:ss, a quote, match quality) and the asynchronous polling behavior: if the search is still running the response says so and you should call again in a minute. That polling contract is exactly the kind of behavior annotations cannot express.

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-loaded with the trigger condition, then required input, then return shape, then exclusions — a sensible order with little waste. The trailing "Free and read only" partially restates the readOnlyHint annotation, which is minor redundancy.

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 single-parameter polling tool with an output schema, the description covers every decision an agent must make: when to call, what to pass, what comes back, and what to do while the job is pending. Nothing material is left to inference.

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 0% and the only parameter is an untyped-purpose "job_id" string, but the description supplies its provenance (the value returned by find_moments) and its required status. It does not say anything about format or validity, but the provenance note is the essential missing piece.

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: fetch the results of a prior find_moments search. It explicitly contrasts with find_moments (start a search) and clip_range (cut a clip), so an agent can select it without opening any 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?

Gives concrete trigger phrases ("what did it find", "show me the matches"), the prerequisite (pass the job_id find_moments returned), and explicit exclusions naming the two sibling tools that handle the adjacent jobs.

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