listVoices

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

Beyond the readOnlyHint annotation, the description discloses important behavioral differences: ElevenLabs allows advanced filtering by name, language, accent, and gender, while other providers only support pagination. This goes beyond annotations by explaining provider-specific constraints, though it stops short of detailing behavior when provider is omitted.

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?

The description is two sentences: the first states the core purpose, the second adds provider-specific context. The 'Tags: Providers' suffix is minor but does not detract. Every word earns its place with no redundancy.

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 the tool's moderate complexity (7 optional params, provider variations) and lack of an output schema, the description covers the key nuance: which providers support advanced filtering vs basic pagination. It does not describe return structure, but the schema covers parameters and the name implies a voice list, making this reasonably 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?

The input schema already provides complete descriptions for all 7 parameters (100% coverage), including 'ElevenLabs only' labels. The description's mention of 'advanced filtering' simply summarizes the schema without adding new meaning, so it meets the baseline but does not exceed it.

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 the tool retrieves voices with filtering and pagination support, using a specific verb and resource. It also distinguishes provider-specific capabilities, setting it apart from sibling tools like getVoice (single voice) and listTTSProviders (providers).

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 provides clear context for when to use the tool and what to expect across providers ('ElevenLabs supports advanced filtering... Other providers support basic pagination only'). It does not explicitly name alternative tools for single-voice retrieval, but the provider-specific guidance serves as practical usage direction.

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