get_mesh_vertex_count

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, not open world), so the bar is lower. The description adds genuine value by enumerating the return fields (vertex_count, vertex_id_count, has_vertex_id_gaps), which is important because no output schema exists.

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?

Two compact sentences, front-loaded with the action, plus an explicit Returns line. The internal API reference (UGeometryScriptLibrary_MeshQueryFunctions::GetVertexCount) is minor overhead but does not derail the structure.

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 a fully described two-parameter schema and no output schema, the description supplies the missing return-value detail. Nothing essential to calling it correctly is absent.

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 coverage is 100%, so both parameters are already documented, and the description adds no syntax or format detail beyond restating lod_index and static_mesh_path. Baseline 3 applies when the schema does the heavy lifting.

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?

States a specific verb ("Count the vertices") and resource ("a static mesh"), making the operation unambiguous. It does not, however, distinguish itself from near siblings such as get_mesh_triangle_count or get_dynamic_mesh_info, though the name itself disambiguates.

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?

There is no when-to-use or when-not-to-use guidance and no named alternative. The only context is that it queries a static mesh, which is already implied by the name and schema.

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