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

The description adds behavioral detail beyond the annotations by stating that size and type are read from storage rather than trusted, and that re-confirming is safe. The idempotentHint annotation already signals retry safety, so the description reinforces it and adds the storage-read insight. No contradiction exists.

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 tight and front-loaded: one verb-focused purpose statement, one behavioral fact, and one retry instruction. Every sentence earns its place, and no filler or redundant restatement of the title appears.

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, idempotent confirmation operation, the description is complete: it covers the trigger condition, the retry behavior, and the fact that storage is the source of truth for size and type. The output schema covers return details, and annotations cover mutability and destructiveness.

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?

Two of three parameters have helpful schema descriptions: id is tied to media_upload, and description explains when to provide it and clarifies never overwriting. The kind parameter has no descriptive text, though the enum values offer some meaning. The main description adds little to parameter semantics beyond its general idempotency statement, so with 67% schema coverage a mid-range score is appropriate.

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 action ('Record a file that finished uploading') on a specific resource, and distinguishes this from media_upload and media_update by framing it as the final recording step after upload. The title 'Confirm a media upload' reinforces the purpose and the sibling names are not ambiguous.

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 gives clear context for when to use it — after an upload has finished — and explicitly says it is safe to call again if the first response was lost. The id parameter description references media_upload, and the description parameter points to media_update for later changes. It lacks a more explicit 'use this instead of X' statement, but the context is clear.

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