sw_insert_fastener

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

Annotations already declare this is a mutating but non-destructive operation, so the description is not on the hook for the safety profile. It does add real behavioral context beyond the annotations – the fastener is created once and reused, and a mate to the hole is created as part of the same call. It does not say what happens if the mate fails, whether repeated calls duplicate components, or whether the new component shows up in sw_list_components.

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?

A single sentence with zero filler, front-loading the action and resource before the placement/mate details. Nothing repeats the title or restates the schema.

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 7-parameter mutation tool with no output schema, the definition covers what it does and its two side effects, and annotations cover the safety profile. It is still thin on outcome details – what the call returns, whether it requires an active assembly, and how it interacts with sw_generate_fastener, which is its closest sibling and a likely source of wrong-tool selection.

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 description coverage is 86%, so the schema already explains size format, length semantics, and the meaning of hole_face_point, seat_face_point, flip, and doc. The description adds nothing about parameters beyond loosely referring to 'a hole' (mapping to hole_face_point) and note that it must be mated. Baseline 3 is appropriate when the schema carries the parameter burden.

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?

The description names a specific verb (insert) and resource (standard metric fastener), and adds scope detail that matters: it is placed into the assembly and mated to a hole. The parenthetical '(generated once, reused)' obliquely distinguishes this from the sibling sw_generate_fastener, but it never names that sibling, so an agent comparing the two still has to infer the difference.

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?

The phrase 'generated once, reused' implies this is the right tool when a reusable library fastener is wanted rather than freshly generated geometry, which is useful implied guidance. However, there is no explicit when-to-use statement, no exclusion, and no mention of prerequisites such as an open assembly document or the relationship to sw_insert_component and sw_add_mate.

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