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

Annotations already cover the safety profile (readOnlyHint true, non-destructive, closed-world), so the description's added value is the conditional return behavior — MP4 link and optional poster only once ready — plus the cost signal "Free", which appears nowhere in the structured fields. It stops short of saying what a non-ready status looks like or whether polling frequency is limited.

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?

Three short sentences, result shape stated up front and the cost note last; nothing is padded or redundant.

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?

With no output schema, the description usefully sketches the return payload (status, progress, MP4 link, poster) and cost. It leaves out possible status values and any error/not-found behavior, which keeps it from being fully complete for a status-polling tool.

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?

Single parameter with 100% schema description coverage that already explains the id comes from create_video, create_ad or list_videos. The description adds no further meaning about the id, so baseline 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 and resource ("Returns a video's status and progress") plus what is included on completion (MP4 link, poster image). It is clearly distinct from create_video/list_videos by being a single-video status read, though it never names a sibling explicitly.

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 phrase "When it's ready" implies polling after creation, which hints at when to call it, but there is no explicit when-to-use or when-not-to-use guidance and no named alternative for listing many videos.

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