query_faces

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

No annotations are supplied, so the description carries the full behavioral burden. It discloses that predicate fields are optional and ANDed and that ordering affects results, but it does not describe return descriptor structure, side effects, permissions, or error behavior beyond 'Returns matching descriptors.'

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 front-loaded with purpose, then uses a tight bullet structure for predicate fields and ends with a concrete example. Every sentence and bullet adds useful information for invoking the tool.

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 nested-predicate query tool with no annotations and no output schema, the description covers the predicate well but leaves two meaningful gaps: the required handle parameter is undocumented, and the returned descriptor shape is only vaguely described.

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%, so the description must compensate. It richly documents the nested predicate object, including kind/type values, normal_dir, radius_eq, area bounds, centroid ordering, and a worked example, though it does not explain the required handle parameter.

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 gives a specific verb and resource: 'Filter faces by a structured predicate. Returns matching descriptors.' This distinguishes it from siblings like list_faces and resolve_face, but it does not explicitly name an alternative or state why an agent would choose this over list_faces.

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?

Usage is implied through the predicate field documentation and a concrete example that finds the topmost +Z-facing face. There is no explicit when-to-use or when-not-to-use guidance relative to sibling tools such as list_faces or classify_face_sides.

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