set_mesh_uv_element_position

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

Annotations already declare readOnly=false, destructive=true, idempotent=true, but the description adds substantial behavior beyond them: an invalid element ID writes nothing and returns is_valid_element=false rather than erroring, there is no undo entry, and the returned actor_name is the component name rather than the actor label. Those are exactly the kind of non-obvious traits an agent needs, and nothing contradicts 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 purpose statement is front-loaded and the returns line is separated cleanly, so an agent gets the operation before the edge-case caveats. It is dense but no sentence is filler; the only mild cost is packing error semantics, undo behavior, and a naming gotcha into one semicolon-joined clause.

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?

There is no structured output schema, so the description must carry return-value information, and it does with an explicit returns object. For a five-parameter mutation it also covers the failure path and undo consequences, leaving little unsaid; only pagination/latency-style operational detail is absent, which is not relevant here.

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 the baseline is 3, but the description adds meaning the schema does not: it pins element_id to a UV-overlay element (not a vertex/edge/triangle) and warns that the returned actor_name is the component name, not the actor label. These clarifications reduce ambiguity in how the identifier parameters map to actual targets.

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 (Set) and a precisely scoped resource: one element of a UV channel overlay on a DynamicMeshActor's live dynamic mesh in the editor world. The element-level granularity plus the editor-world/live-mesh qualifier cleanly separates it from UV siblings such as translate_mesh_uvs, set_triangle_uvs, set_mesh_uvs_from_projection, and copy_mesh_uv_channel.

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 conveys the context of use (live dynamic mesh on a DynamicMeshActor in the editor world) and the failure path for an invalid element ID, so the intended usage is inferable. However, it never names an alternative tool or states when NOT to use this in favor of a sibling UV tool, so the guidance is implied rather than explicit.

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