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. It states 'Get multiple Faces by IDs' but doesn't disclose behavioral traits such as read-only vs. mutative nature, error handling for invalid IDs, rate limits, or return format. This is a significant gap for a tool with no annotation coverage.

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, making it easy to parse. It's appropriately sized and front-loaded, delivering the core purpose immediately without unnecessary elaboration.

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, no output schema, and a simple parameter schema, the description is incomplete. It lacks details on behavior, error handling, return values, and differentiation from siblings like 'listFaces'. For a retrieval tool in a complex 3D modeling context, this leaves significant gaps for an AI agent.

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 'ids' documented as 'Face identifiers'. The description adds minimal value beyond the schema by implying retrieval of multiple items, but doesn't provide additional context like ID format or constraints. 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 action ('Get') and resource ('multiple Faces by IDs'), making the purpose understandable. However, it doesn't differentiate from sibling tools like 'listFaces' or 'getFaces' (if that existed), which would specify scope or filtering differences. It's specific but lacks sibling distinction.

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 like 'listFaces' or other 'get' tools for Faces. The description implies retrieval by IDs but doesn't specify prerequisites, context, or exclusions, leaving usage unclear relative to siblings.

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