fill_faces

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 the tool creates faces from edges, but does not disclose whether edges must be pre-selected, if the new face is automatically selected, or if the operation modifies the mesh in-place. Minimal behavioral context for a mutation tool.

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?

Description is extremely concise: one-line summary, two short usage sentences, param description, and return type. No fluff, front-loaded with the key action. Every sentence earns its place.

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 tool's simplicity (1 param, output schema exists but not shown), the description covers main purpose and return. However, it omits prerequisites ('selected edges' is implied but not stated) and assumes a closed edge loop without noting failure conditions. Adequate but with gaps.

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 0%, and the description adds 'Name of the mesh object' for the single parameter, which is slightly more specific than the schema title 'Object Name.' Baseline 3 is appropriate as the description provides minimal additional meaning beyond the schema.

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?

Description clearly states 'Fill selected edges with a face' and 'Creates faces from a closed edge loop.' It specifies the verb (fill/creates) and resource (edges/face). Distinguishes from siblings like bridge_edge_loops or grid_fill by focusing on 'closed edge loop' and 'capping open ends,' though not explicitly differentiating.

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?

Description includes 'Useful for closing gaps in meshes or capping open ends,' providing clear context for when to use. However, it lacks guidance on when not to use or alternatives (e.g., bridge_edge_loops, grid_fill). No exclusions or prerequisites mentioned.

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