3D-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. 'List all Faces' implies a read-only operation but doesn't specify whether it's paginated (though parameters suggest it might be), what format the results take, or if there are performance considerations. For a tool with 4 parameters and no output schema, this leaves significant gaps in understanding how it behaves.

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 extremely concise at just three words, with zero wasted language. It's front-loaded with the core action ('List all Faces'), making it immediately understandable. Every word earns its place, though this brevity comes at the cost of completeness.

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 complexity (4 parameters, no annotations, no output schema, many sibling tools), the description is inadequate. It doesn't explain what 'Faces' are in this context (3D modeling faces vs. other types), how results are structured, or how this differs from similar tools. For a listing operation in what appears to be a 3D modeling system, more context is needed for effective use.

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 schema description coverage is 100%, with clear documentation for all 4 parameters (filters, limit, offset, parentId). The description adds no parameter information beyond what's in the schema, so it meets the baseline of 3. However, it doesn't compensate by explaining how parameters interact (e.g., how filters combine with parentId) or provide examples.

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 'List all Faces' clearly states the verb ('List') and resource ('Faces'), making the basic purpose understandable. However, it doesn't distinguish this tool from similar sibling tools like 'getFaces' or 'list' operations for other resources (e.g., 'listEdges', 'listVertexs'), leaving ambiguity about what makes this specific listing operation unique.

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 no guidance on when to use this tool versus alternatives. With sibling tools like 'getFaces' (which might retrieve specific faces) and 'query' (which might offer more flexible searching), there's no indication of when this listing approach is preferred or what its limitations are. The agent must infer usage from the tool name alone.

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