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

Annotations are minimal (readOnlyHint=false, destructiveHint=false, openWorldHint=false), so the description carries the burden and does so well: it discloses storage in Cloudflare R2, headless-browser processing, that the input is deleted when the job ends, and that output download links expire after 1 hour. These are non-obvious lifecycle behaviors an agent needs.

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?

Purpose is front-loaded in the first sentence, followed by parameter notes and then the storage/lifecycle details. It is somewhat dense with infrastructure detail, but each sentence conveys actionable information rather than filler.

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 processing tool with nested input objects and no output schema, the description covers input requirements, output-link expiration, and job lifecycle well. Minor gap: it frames input as 'one file' while the schema allows up to 12 items, leaving the multi-file case slightly ambiguous.

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 the baseline is 3, but the description adds meaning: it clarifies outputFormat examples, that bitrateKbps applies only 'where the tool supports them', and ties settings to a 'set_transcript_layout: paragraphs' option. This goes beyond restating the schema fields.

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 ('Transcribes the speech in a recording to text') and names the underlying technology (Whisper). This clearly separates it from siblings like subtitle_generator or waveform_generator, though it does not explicitly name an alternative it is not.

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?

There is no explicit when-to-use, when-not-to-use, or sibling routing guidance. An agent must infer from the purpose that this is the transcription tool versus e.g. subtitle_generator, with no stated conditions or prerequisites for choosing it.

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