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

Annotations already flag destructiveHint=true and idempotentHint=false, and the description adds genuinely useful context the annotations cannot convey: the URL expires, the bytes are PUT out-of-band rather than passed as a parameter, and the resulting upload_id feeds create_voice. It omits the expiry window and whether abandoned uploads are cleaned up, which would be the remaining value-add.

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 short sentences, zero filler, and the core action plus the full two-step workflow are front-loaded. Every clause earns its place by describing a distinct step the agent must perform.

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?

An output schema exists, so return values need no explanation, and the workflow and expiry are covered. However, for a 2-parameter tool at 0% schema description coverage, the description leaves both inputs undefined, which is a real completeness gap for an agent deciding what filename to supply.

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 carry both parameters, yet it explains neither. It never says that 'filename' determines the accepted audio extensions (mp3/wav/m4a/flac/ogg/webm) nor what 'request_id' is for — a notable gap given idempotentHint=false makes the idempotency-key role of a UUID request_id non-obvious. The only identifier it mentions, upload_id, is not a parameter of this tool.

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 — 'Create an expiring audio upload URL' — and immediately places it in the voice-creation flow, naming create_voice as the follow-up. An agent can distinguish this pre-upload step from create_voice and verify_voice 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?

The description gives an explicit sequence: create URL, PUT the bytes there, then call create_voice with the upload_id and consent. That is clear usage context, but it never states when not to use it (e.g. when an existing upload_id is already available, or that the URL expires and must be re-requested).

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