transcribe_file

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

With no annotations, the description must carry the behavioral burden, and it does disclose engine selection, API-key switching, and the file-readable requirement. However, it omits meaningful behavioral traits such as potential third-party data transmission when using the OpenAI API, model download behavior, or format/duration limits.

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 sentences, front-loaded with the main purpose, followed by engine-selection notes and a constraint. There is no filler; every sentence contributes 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 6-parameter tool with no annotations, the description covers the core call path and output shape, and the output schema covers return values. But optional parameter semantics and behavioral caveats are missing, so an agent cannot fully reason about non-default invocations.

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 compensate. It adds semantics only for file_path (must be readable) and api_key (selects OpenAI API), while task, model, prompt, and language remain unexplained in both schema and description.

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?

Description specifies verb 'Transcribe', resource 'local audio or video file', and expected return 'JSON with text and timestamps', so the tool's function is unambiguous. There are no siblings to differentiate from, and the name is reinforced without being a mere tautology.

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?

It gives concrete context: the default local Whisper path, when to switch to OpenAI speech API via api_key (or OPENAI_API_KEY), and a prerequisite that the MCP server must be able to read the file. It doesn't name alternative tools, but no siblings exist and the backend-selection guidance is enough for an agent to proceed correctly.

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