fanar_text_to_speech

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

With no annotations, the description carries the full burden and does well on output: it saves to a file and returns the file path. It also discloses a rate limit (~20 requests/day) and a model precondition. It omits permission/auth needs, whether files persist or are overwritten, and text-length 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?

Two dense sentences, front-loaded with the core action and output artifact, followed by the model caveat and quota. Little waste. The trailing 'About 20 requests a day' is terse and slightly ambiguous as to whether it is a hard cap or a soft guideline.

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, no output schema, and 0% schema descriptions, the coverage of output form and rate limits is helpful but leaves voice/language pairing, format selection, and file-naming behavior undocumented anywhere. Adequate, not complete.

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 6 parameters, so the description must compensate and only partially does. It explains the model enum values and hints at quran_reciter, but says nothing about the 10-value voice enum (which voices suit Arabic vs English), filename, or response_format.

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: synthesize Arabic/English text into an audio file and return the path. That is unambiguous and clearly distinct from siblings like fanar_transcribe (the inverse) or fanar_chat. It stops short of naming an alternative sibling or contrasting explicitly, so it is not quite a 5.

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?

Gives a concrete routing condition: Qur'an recitation by a named reciter requires Fanar-Sadiq-TTS-1, implying Fanar-Aura-TTS-2 otherwise. It also surfaces a practical quota (~20 requests/day). No explicit when-not or alternative-tool guidance, but the model-selection rule is real, actionable context.

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