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

Annotations cover the safety profile (non-read-only, idempotent, non-destructive, closed-world), and the description adds the failure mode ('expired or invalid uploads are rejected') plus what is actually checked (content, size, ownership). It does not spell out the retry/re-upload path, but that is a meaningful addition beyond the structured hints.

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 tight sentences: prerequisite first, then verification behavior and output, then failure handling. No filler and nothing buried.

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 an output schema present, the description need not explain the returned mediaId structure, and it correctly focuses on sequencing, verification scope, and rejection behavior. Only the semantics of the input identifier remain thin.

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% for the single uploadIntentId parameter, so the description must carry the load. It implies the identifier originates from the create_media_upload call, which is useful, but never names the parameter or states its format/lifetime.

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 (verify/finalize an uploaded file) and distinguishes itself from siblings by naming both the producer (create_media_upload) and the consumer (attach_media). An agent can place this tool in the workflow without opening any schema.

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?

Explicitly gives the ordering condition: use after uploading bytes to the URL returned by create_media_upload. It does not state when not to use it or what to do on rejection, but the workflow context is unambiguous.

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