poly_select_faces

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

Annotations already supply readOnlyHint=false and destructiveHint=true, and the description adds meaningful behavioral context beyond those: it leaves the selection active, enters face sub-object mode, and returns the selected face indices. This is important side-effect information for an agent deciding whether to chain it with other poly tools. There is no contradiction with the annotations.

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 first, then the side effect, then the return value. The bilingual structure is not wasteful because it serves both language audiences, and every sentence contributes useful information.

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 an 8-parameter tool with no output schema, the description covers the core contract well but leaves important invocation details implicit. Missing rules about filter combination, the effect of providing no selection criteria, and whether height bounds require heightAxis are gaps an agent would need to resolve before calling the tool correctly in complex cases.

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 baseline is 3; each parameter already has a bilingual description. The main description restates the selection modes but does not add cross-parameter semantics, such as whether multiple non-index filters combine with AND or OR, whether heightMin/heightMax can be used independently, or what happens when no criteria are provided.

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 opens with a specific verb and resource: 'Select faces by index, material ID, normal direction or height range.' It also distinguishes itself from read-only tools like poly_get_faces and more specialized selectors like poly_loop_select or poly_ring_select by describing its multi-criteria face selection behavior and the active sub-object selection side effect.

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 explicitly frames the tool as a prerequisite for follow-up operations: 'Returns the selected face indices so you can follow up with poly_extrude_faces etc.' This gives clear context for when to use it. However, it does not explicitly name alternatives or state when not to use it, so it stops short of a 5.

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