compare_stt

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

With no annotations, the description carries the full burden and mostly delivers: it discloses hard limits (30 s, 10 MB, clips/ folder only, URL rejection), the no_key_configured edge case, and a prompt-injection warning that transcripts are untrusted data. It omits whether the calls are billable/rate-limited and whether there are side effects, so it stops short of a 5.

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?

Front-loaded with the action and its constraints, followed by the per-provider return shape, the default for `reference`, an edge case, and a one-line safety note. Dense but every clause adds information an agent needs.

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 4-parameter tool with no annotations, no output schema and 0% schema coverage, the description supplies the return fields, defaults, and limits, which is nearly enough. The gaps are the undocumented `language` parameter and whether providers default to all configured ones.

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 0%, so the description must compensate, and it does for three of four parameters: audio_path (format, size, location restrictions), reference (defaults to clips/<name>.txt), and providers (semantics revealed via the no_key_configured behavior). The `language` parameter is never mentioned, leaving its expected format unspecified.

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?

Specific verb+resource: it sends one audio clip to all configured STT providers and returns a per-provider comparison of transcript, CER, WER, latency and cost. That scope ('compare across providers') is clearly distinct from the sibling tools list_providers and estimate_cost.

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?

Input constraints imply usage ('one short clip', repo clips folder only, URLs refused) and the no_key_configured behavior tells the agent what to expect, but it never states when to prefer this over estimate_cost (cost preview) or list_providers (discovery). The agent must infer the routing.

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