3D-MCP

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

With no annotations provided, the description carries full burden for behavioral disclosure. 'Create multiple Faces' implies a write/mutation operation, but it doesn't specify whether this is destructive to existing data, requires specific permissions, has side effects, or how failures are handled. For a creation tool with zero annotation coverage, this leaves significant behavioral questions unanswered.

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. However, this brevity comes at the cost of being under-specified for a complex creation tool. While structurally efficient, it lacks the necessary explanatory content that would make it truly helpful.

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?

For a creation tool with no annotations, no output schema, and complex nested parameters (faces with normals, vertex IDs, materials), the description is incomplete. It doesn't explain what Faces are, how they relate to other entities (meshes, vertices), what happens on creation, or what the tool returns. The agent must rely entirely on the input schema for understanding.

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 the schema fully documents the single 'items' parameter and its nested properties. The description adds no parameter information beyond what's in the schema. According to scoring rules, when schema coverage is high (>80%), the baseline is 3 even with no param info in the description.

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 'Create multiple Faces' states the action (create) and resource (Faces), but it's vague about what Faces are in this 3D modeling context and doesn't differentiate from sibling tools like createEdges, createVertexs, or createMeshs. It restates the tool name without providing specific context about what Faces represent in the system.

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 like createMeshs, createEdges, or updateFaces. There's no mention of prerequisites (e.g., needing existing vertices or meshes), typical workflows, or exclusion criteria. The agent must infer usage from the parameter schema alone.

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