Upload and processing status

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

Annotations already establish readOnlyHint and openWorldHint, but the description adds real value beyond them: it discloses that the call can block and wait for state changes, and it enumerates the returned aspects (progress, errors, resulting video, failure/rejection states, private-lock check). It does not state the maximum wait or that waiting holds a connection, but the schema covers the wait bound.

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?

A single dense sentence that front-loads the primary purpose and then adds the secondary mode and the wait capability. The 'and/or' construction is slightly ambiguous but compact enough to justify its length.

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 does a good job enumerating what comes back, and with zero required parameters it explains the two identifier modes. The remaining gap is the all-optional-parameter case — what happens if neither job_id nor video_id is supplied — plus the relationship between an upload job and its resulting video, which an agent polling for completion would need.

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 only 50%, and the two undocumented parameters are exactly job_id and video_id. The description partially compensates by mapping each to a different mode (upload job status vs. video processing state), which is genuine meaning beyond the bare schema. It still omits identifier format, whether both may be combined, and behavior when both are absent.

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 names a specific resource (upload job / video processing state) and enumerates what it reports: progress, errors, resulting video, and the 'locked to private' restriction. It is clearly a read-only status/polling tool, distinguishable from list_uploads and cancel_upload by its per-item focus, though it never names those siblings 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 'and/or' phrasing implies that supplying job_id queries the upload job while supplying video_id queries YouTube's processing state, which is useful implicit routing. However, there is no explicit statement of when to prefer this over list_uploads or get_video, and no instruction on what to do when neither identifier is provided even though zero parameters are required.

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