List Faces

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

The description adds meaningful behavioral detail beyond the readOnlyHint and openWorldHint annotations: it explains that tags are stable across geometry edits only as long as key geometric descriptors remain unchanged, and it lists the optional fields in the return value. This helps the agent understand the semantics of the returned tags.

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 compact and front-loaded: it states the action, the return format, the stability behavior, and the recommended usage in three focused sentences. No filler or redundant restatement of the tool name or annotations.

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 simple read-only list tool with one parameter and no output schema, the description covers the return shape, optional fields, and tag stability. The only notable gap is the lack of explicit explanation for the 'handle' parameter, but the overall context is sufficient for the agent to understand the tool's behavior.

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 has one required parameter, 'handle', with no description beyond its title, and schema coverage is 0%. The description discusses faces of a 'shaped object' but never explicitly explains that the handle identifies that object, leaving a meaningful semantic gap.

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 that the tool lists all faces of a shaped object and returns stable tags plus geometric descriptors. It is specific about the resource (faces) and the output, though it does not explicitly differentiate itself from sibling tools like query_faces or classify_face_sides.

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 gives clear context: tags survive geometry edits under stated conditions, and the tag should be used instead of the FaceN index in subsequent calls. It does not explicitly mention alternative tools or exclusions, but it provides actionable guidance for when and how to use the returned data.

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