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

Annotations already declare readOnly/destructive=false and openWorld=false, so safety is covered. The description adds genuinely useful behavioral context – that download_url appears only when the rendered MP4 exists – but omits the status values or terminal states an agent needs to decide when polling is finished.

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 core action first and the conditional-output caveat second. No wasted text for a simple single-param read tool.

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 simple polling read tool with annotations covering safety and a single documented param, this is adequate but incomplete: the status values, whether polling should continue, and the response shape (no output schema exists) are left unexplained, and only the download_url condition is surfaced.

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 a single required parameter and 100% schema description coverage (including the 'job_id from clip_video' note), the schema does all the work. The description adds nothing beyond it, so the baseline of 3 applies.

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 (poll) and resource (clip job), which is clearer than the bare name. However it doesn't distinguish itself from parallel status tools like get_import_status, get_music_video_status, or get_status, so an agent must infer the resource distinction from the name alone.

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?

'Poll a clip job' implies the polling use case but gives no explicit when-to-use guidance, no mention that job_id comes from clip_video (that detail lives only in the schema), and no indication of how often to poll or when to stop.

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