fusion_thread

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

Annotations already establish that this is a non-readonly, non-idempotent mutation. The description adds a useful behavioral hint by saying modeled=True creates real geometry, but it does not describe result/error behavior, reversibility, or any side effects beyond that hint.

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 description is two clear sentences with no filler. The critical face-source information is front-loaded, and each clause adds useful guidance.

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 the required/default path this is workable: an agent knows which face to pass and can use defaults. With 8 parameters, no output schema, and no hints for body sourcing or thread option values, the description is not fully complete for advanced uses.

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 0%, and the description compensates for a few key parameters: face is explained as the non-planar face from fusion_list_faces, and internal/modeled get meaningful semantics. However, the remaining params — body, handedness, designation, thread_type, thread_class — are left only to their schema names/defaults.

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: it adds a thread to a cylindrical face. It also points to the exact source of the face index and flags the relevant face type, so it is clearly differentiated from sibling operations such as listing/creating holes or other features.

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 clear working context: use it on the non-planar face from fusion_list_faces, and use the internal/modeled flags for the two common variants. It does not explicitly name an alternative when the agent should prefer fusion_hole or when a thread should not be added, so it stops short of full when-not guidance.

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