Query Faces

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

Annotations already cover read-only and closed-world behavior; the description adds meaningful details about ANDed predicate matching and optional ordering. It does not disclose the structure of the returned descriptors, tolerance defaults, or behavior with unknown predicate keys, but these gaps are somewhat mitigated by the readOnlyHint.

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 well-structured with bullet lists and a concrete example. It front-loads the purpose and includes no filler; every sentence adds operational value.

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 read-only query tool with no output schema, the description covers the core predicate and ordering behavior well. It is incomplete regarding the required handle parameter, return descriptor format, defaults for tolerances, and error/empty-result behavior, so an agent still has meaningful unknowns before calling it.

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 predicate parameter is documented in depth with allowed values, units, and an example, which is critical since schema description coverage is 0%. However, the required handle parameter is completely unexplained, and tolerance fields like normal_tol and radius_tol are referenced but not defined.

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 uses a specific verb ('filter') and resource ('faces'), and immediately states what is returned ('matching descriptors'). The predicate fields make the scope precise and distinguish it from an unfiltered face-listing tool, though it does not explicitly name sibling alternatives like 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?

The description clearly conveys that this tool is for predicate-based face filtering and includes a concrete example, so usage context is implied. However, it never states when not to use it or names alternatives such as list_faces, resolve_face, 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.