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

Annotations already declare readOnly, idempotent, non-destructive, open-world behavior, so the safety profile is covered. The description usefully adds that cloned voices originate from mureka_clone_voice and that last_id drives pagination, but does not add further operational context such as rate limits or result ordering.

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?

Dense but front-loaded: the core action and scope come first, then mode semantics, then pagination, then the sibling exclusion. No sentence is filler.

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?

With no output schema, the description compensates by enumerating returned fields (title, language, description, voice_id) and the pagination contract. It also names the endpoint, so an agent has everything needed to call and consume the result.

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 100%, so baseline is 3. The description reinforces the cloned true/default-false distinction and the last_id paging pattern, but adds little syntax or format detail beyond what the schema already states.

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 ('List speech voices') and immediately disambiguates scope: speech voices for mureka_create_speech versus singing voices handled by mureka_list_vocals. An agent can distinguish it from every list_* sibling without opening a schema.

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 names the alternative explicitly (mureka_list_vocals for singing voices) and gives the conditional that switches mode ('with cloned: true the ones you cloned with mureka_clone_voice'). It also ties the output to its downstream consumer, mureka_create_speech.

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