form_crease

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

With no annotations, the description carries the full burden and does so: no stable edge ids, failure mode INVALID_PARAMS with details.nearest for missing or ambiguous points (symmetric meshes), atomic rollback of already-changed crease flags, and the exact return shape {body, changed}.

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 core action is front-loaded in the first clause, then picking mechanics, then failure and rollback behavior, then the return value. Every sentence supplies information an agent needs to call the tool correctly.

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 5-parameter mutation tool with no annotations and no output schema, the description covers selection method, unit semantics, error behavior, atomicity, and return value. Nothing material is missing.

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 semantics: `near` must be edge midpoints sourced from form_inspect, the units default of mm, and that `tolerance` governs nearest-edge matching and ambiguity failure. That meaning goes beyond the schema text.

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 pair (crease/uncrease) acting on a named resource (control-mesh edges of a T-spline body) and discloses the side effect that the B-Rep is regenerated. It is clearly distinguishable from siblings such as form_inspect or form_convert_to_brep.

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?

Explains how to select edges in practice (take exact edge midpoints from form_inspect) and what conditions cause failure. It stops short of explicit when-not-to-use guidance or naming alternative tools for edge selection, which keeps it from a 5.

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