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

Annotations already signal readOnlyHint, idempotentHint, and destructiveHint. The description goes far beyond by detailing the status lifecycle (including awaiting_upload, queued, finished, error), explaining what each state returns (e.g., uploadExpiresAt, resultUrl, retryVoucher), and even noting that bad tokens vs unknown jobIds both return not_found deliberately. No contradictions.

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 single dense paragraph that packs a lot of information without wasted words. It front-loads the purpose and token requirement, then efficiently covers the status lifecycle. While it's somewhat long, every sentence adds value, so it earns a high score for conciseness given the complexity.

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?

Despite no output schema, the description fully documents what the response contains for each status (uploadExpiresAt, resultUrl, thumbnailUrl, durationMs, retryVoucher), including the 24-hour free re-download window and redirect behavior. It also covers edge cases like awaiting_upload not having an uploadUrl. For a tool with this complexity, the description is complete.

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 descriptions for jobId and token. The description adds critical context: it explains that the token is the 't' query parameter of the statusUrl and warns that the token cannot be regenerated, which is essential for correct usage and not evident from the schema alone.

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 explicitly states it is a 'Free status lookup for a job accepted by' and lists three specific sibling tools (convert_video, probe_media, extract_frames), making the verb+resource highly specific and clearly distinguishing it from other tools.

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 explains when to use the tool (after job acceptance), what is required (ownership token from statusUrl), and provides critical guidance on storing the token because it cannot be regenerated. It does not explicitly state when not to use it, but the context is clear enough for an agent to decide.

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