sheet_metal_contour_flange

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

With no annotations, the description carries the full burden and does: it discloses the preview-API risk and exact failure signature (FUSION_API_ERROR reason=api_unavailable, nothing changed), the rollback behavior on failure ('the previous rule restored'), and specific parameter-combination validation errors. This is mutation-relevant context an agent could not infer from the schema.

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 definition, then workflow, then failure modes, then return shape, then example — a good ordering with no filler sentences. The line-broken formatting and one long parenthetical make it slightly harder to scan than an ideal 5.

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 10-parameter mutation tool with no output schema, the description still lists the returned keys (feature, health, created_bodies, modified_bodies, removed_bodies, rule), covers the API-availability prerequisite, and supplies a runnable example call. Nothing essential to invoking it correctly 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 baseline is 3; the description goes beyond it by explaining that 'profiles' are the bend-line curves (with an L-of-two-lines example) and by spelling out the two_sides/distance_two constraint that the schema only hints at via enum descriptions. Marginal gains remain for rule_source/rule_source interaction, keeping it below 5.

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?

Names a specific verb+resource (contour flange) and immediately defines it operationally: a bent sheet metal body from an open sketch profile, with the profile being the bend-line shape and thickness/radius coming from the rule. It is clearly distinguished from siblings, which it names by role (sheet_metal_edge_flange for edge bends, sheet_metal_list_rules/capabilities).

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 an explicit recommended sequence (rule -> contour flange -> edge_flange on outer edges -> list_bends/unfold/refold -> flat pattern -> export) and states when NOT to reach for this tool: 'Bend along a sketch line is not available in the Fusion API: add bends with edge flanges or draw them into the contour.' It also directs the agent to check sheet_metal_capabilities first.

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