form_insert_edge

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: it discloses the preview-API dependency and the exact failure (FUSION_API_ERROR reason=api_unavailable, nothing changed), the single-loop restriction, the ambiguous/too-far point failure with INVALID_PARAMS and details.nearest, and atomicity ('nothing is changed'). It also states the return payload shape.

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 purpose, then the API-dependency caveat, then input sourcing, then return value — a sensible order with no filler. The prose is dense and the parenthetical mid-sentence break slightly hurts scannability, but every sentence carries 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?

No output schema exists, yet the description spells out the return object, the failure modes, and the no-op guarantee, which is everything an agent needs to call a mutation tool safely. Nothing material is left implicit for a 7-parameter operation.

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; the description goes beyond it by explaining that `near` should be exact edge midpoints taken from form_inspect and that units default to mm, which the schema only says as '[x, y, z] in `units`'. It adds nothing about mode, position, or both_sides, leaving those entirely to the schema.

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 ('Insert edges next to control-mesh edges of a T-spline body') plus the downstream effect ('the B-Rep is regenerated'), and references the sibling form_inspect for sourcing input points. An agent can distinguish this from form_move/form_crease/form_convert_to_brep without opening any schema.

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 a clear workflow prerequisite — obtain exact edge midpoints from form_inspect — and states the constraint that all edges must belong to one loop. It does not name a when-not-to-use case or an alternative tool for adjacent operations, so it stops just 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.