Merge meshes

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

Annotations already declare destructiveHint=true, idempotentHint=false, and readOnlyHint=false, so the description only needs to add context — and it does: it discloses the geometric success conditions and the cell-size rule that governs the result. It stops short of saying what happens to the source meshes on success or how failure is reported.

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?

Front-loaded with the action, then constraints, then the helper tool reference — four tight sentences with no filler. The appended bulc-mcp rules tag adds housekeeping noise but is a convention, not prose bloat.

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 destructive, non-idempotent, two-parameter operation with no output schema, the description supplies the geometry preconditions and the choice semantics that determine success. The remaining gap — whether the source meshes are consumed and what a failure returns — is minor but noticeable for a destructive tool.

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 real meaning beyond the enum text: 'choice' only matters when cell sizes differ, and the union must divide into a whole number of the chosen cells. It also ties 'indices' to list_meshes for obtaining valid values.

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 and resource ('merge several meshes back into one') and explicitly anchors it as the inverse of slice_mesh, which no sibling name conveys on its own. An agent can distinguish this from slice_mesh, set_meshes, and auto_multimesh immediately.

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?

Gives concrete preconditions ('only when the selected meshes do not overlap and their union is exactly a box') and routes the agent to list_meshes for index numbers. It does not spell out when to prefer an alternative such as slice_mesh or auto_multimesh, so it stops short of full when/when-not guidance.

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