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

With no annotations, the description carries the full burden and only discloses pricing ('Cost: 2 credits'). It says nothing about whether audio_url and audio_base64 are mutually exclusive (both are non-required, which is ambiguous), supported formats or duration limits, authentication needs, or failure behavior.

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 with zero filler, and the core capability is front-loaded ahead of the cost note. Nothing here is redundant or padded.

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?

No annotations and no output schema exist, yet the description omits the things an agent actually needs: input-mode selection between URL and base64, format/size limits, duration caps, and any sense of the response payload beyond 'timestamps'. For a 3-parameter tool with ambiguous required fields, this is too 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 100%, so each parameter is documented in the schema itself and the baseline is 3. The description adds no parameter meaning beyond that — notably it does not clarify that the two audio inputs are alternatives.

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 audio to text') plus an output trait (timestamps), which is clear on its own. However, no sibling differentiation is offered even though the sibling list contains a 'transcribe' tool, so an agent cannot tell from the description alone which one to pick.

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 when-to-use guidance, no prerequisites, and no mention of the overlapping 'transcribe' sibling. The agent gets no help deciding between stt, transcribe, or subtitle.

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