VOICEVOX TTS MCP

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions 'Get detail' but doesn't specify if this is a read-only operation, what permissions are needed, error handling, or response format. This leaves significant gaps for a tool that likely interacts with a speaker database.

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 a single, efficient sentence with no wasted words. It's front-loaded with the core action ('Get detail'), making it easy to scan and understand quickly.

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 no annotations and no output schema, the description is incomplete. It doesn't explain what 'detail' includes (e.g., speaker attributes, capabilities), potential errors, or how this fits with sibling tools like 'synthesize_file'. For a tool with one parameter but unknown behavioral traits, more context is needed.

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%, with the parameter 'uuid' documented as 'Speaker UUID (speaker uuid)'. The description adds no additional meaning beyond this, such as format examples or where to obtain the UUID. Baseline 3 is appropriate since the schema does the heavy lifting.

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 verb ('Get detail') and resource ('speaker'), making the purpose understandable. However, it doesn't differentiate from sibling tools like 'get_speakers' (which likely lists speakers) or explain what 'detail' entails beyond the ID lookup.

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?

No guidance is provided on when to use this tool versus alternatives. For example, it doesn't clarify if this should be used after 'get_speakers' to fetch more information or in what contexts (e.g., before synthesis). The description only states the basic function without context.

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