fetch_video_download

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It discloses the return type, an important strict-input rule (never trim query parameters), and clarifies that expires_at is separate metadata rather than part of the URL—all meaningful context beyond the tool's name. It does not mention expiration/error behavior, which prevents a perfect score.

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 compact sentences with no filler. The core purpose is front-loaded in the first sentence, and the second sentence adds only the critical usage detail about the URL format. Every word earns its place.

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 tool with no output schema and no annotations, the description adequately covers the input and return shape, but it omits max_bytes semantics, expiration or error conditions, and the expected sequencing with wait_for_video_project or video_projects_retrieve_details. It is sufficient for a straightforward call but incomplete for robust agent decision-making.

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 description coverage is 0%, so the description must compensate for the lack of property descriptions. It explains download_url thoroughly, including the exact signed URL requirement and the query-parameter caveat, but it entirely omits any explanation of max_bytes, leaving that parameter underdocumented.

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 states a specific verb ('Fetch'), a clear resource ('a video downloads[n].url'), and a return format ('embedded MCP binary resource'), which distinguishes it from the audio and image download siblings. It is neither tautological nor vague—it precisely names what the tool does and what input it expects.

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 implies the correct usage context: the video project must be completed and the caller must already possess the signed URL. It does not explicitly name alternative tools like wait_for_video_project or video_projects_retrieve_details, nor does it state when not to use this tool, leaving some routing to inference.

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