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

With no annotations, the description carries the full burden and does disclose genuinely non-obvious behavior: accepted formats (mp3, wav, m4a, mp4 and more), a 25 MB hard size cap, and per-plan rate limits (3/day free vs 300/day fair use). It does not say whether calls are synchronous or queued, nor what the transcript looks like (timestamps, speakers, language handling).

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 short sentences, zero filler, action stated first and operating limits immediately after. Every sentence carries distinct 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 one-parameter tool with full schema coverage and no output schema, this covers the essentials an agent needs before calling: what it accepts, how big, and how often. The main remaining gap is the shape of the result and whether transcription is synchronous.

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% for the single required parameter and already documents that audio_url must be a public http(s) URL. The description adds no URL syntax detail but supplies the size constraint that governs whether a given URL is acceptable.

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 ('Transcribe an audio or video file to text'), and explicitly widens scope to video as well as audio. The only sibling, get_usage, is an unrelated quota-read tool, so differentiation is unambiguous.

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?

Supported formats and the 25 MB cap imply when the tool is usable, but there is no explicit when-to-use/when-not guidance or prerequisite statement. Constraint facts are not the same as routing guidance.

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