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

Annotations declare readOnlyHint=false, but the description clarifies the tool has side effects (enqueues transcription, marks files ready). It also explains that text/PDF skip transcription, which is valuable behavioral info. However, it doesn't state what happens on failure or if it's idempotent.

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 concise (two sentences) and front-loaded with the main purpose and the key partition between media types. It earns its place by prioritizing the most decision-relevant information.

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 8 parameters and no output schema, the description covers the essential flow (confirm upload, transcription behavior) but omits details like return value or error cases. Given the complexity and annotations, it's fairly complete but not exhaustive.

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%, so parameters are already well-documented. The description adds context that 'language' is used only for audio/video and not for text/PDF, and that multipart_parts/multipart_upload_id are for multipart uploads. This adds meaningful guidance beyond the schema.

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 clearly states it confirms a completed R2 upload for an Inbox interview and distinguishes between media types (audio/video get transcription, text/PDF do not). It specifies the tool's role in the upload flow. It doesn't explicitly differentiate from siblings like mcp_prepare_upload or mcp_sign_upload_parts, but the purpose is evident from the description.

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 it should be used after completing the upload (single PUT or multipart) and references the prepare step for keys. It doesn't explicitly name alternatives or when not to use it, but the context signals and flow are reasonably clear given the sibling names.

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