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

Annotations already indicate read-only, idempotent, non-destructive behavior. The description adds value by detailing the number of voices (54), languages (9), and return structure (id, name, gender, accent, lang, grade). No contradictions.

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?

Very concise: one-line purpose, bulleted args and returns. No fluff; every sentence adds value. Front-loaded with core verb and resource.

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?

Given low complexity (1 optional param, no output schema), the description fully covers purpose, parameter usage, return format, and relation to siblings. No gaps.

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 100% (1 parameter with description). The description adds real-world context: 'e.g. 'pt-br', 'en-us'' and default behavior ('omit for all 54 voices'), enriching the schema.

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?

The description clearly states 'List available TTS voices with metadata' and provides specifics (54 voices, 9 languages). It distinguishes itself from siblings: 'check_tts_service' (presumably service health) and 'synthesize_speech' (which uses a voice ID).

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 description mentions optional language filter and notes the voice ID is used in 'synthesize_speech', guiding usage. However, it doesn't explicitly state when not to use this tool versus siblings, though the context is clear.

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