openai_generate_speech

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

With no annotations supplied, the description carries the full behavioral burden, and it does disclose the key trait: generated audio is written to local disk rather than returned inline. However, it says nothing about where the file lands, whether an existing file with the same name is overwritten, what the default filename or extension becomes, or any rate/cost considerations.

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, front-loaded with the action and its side effect, with no filler. The brevity is appropriate, though the second sentence is a constraint rather than a structural aid to understanding the parameters.

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?

An output schema exists, so return values need not be described, but for a 7-parameter mutation tool with zero annotation and zero schema coverage the description is too thin. Missing are the meaning of the tuning parameters (voice, speed, response_format, instructions) and the file destination/overwrite behavior implied by "save it locally".

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% across seven parameters, so the description must compensate and largely fails to. It only hints at model (must be endpoint-supported), input_text, and filename ("save it locally"); voice, speed, response_format, and instructions are left entirely unexplained in both schema and prose.

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?

"Generate speech audio and save it locally" gives a specific verb plus resource and notes the file-writing side effect, which distinguishes it from siblings like openai_transcribe_audio and openai_generate_image. It stops short of explicitly naming those siblings as alternatives, but the operation itself 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?

The only guidance is "Supply a model supported by the current speech endpoint" - a constraint, not a when-to-use rule. There is no mention of when this should be preferred over openai_transcribe_audio (the inverse operation) or any prerequisite such as API key scope or output directory.

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