assembly_add_part

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

Annotations declare readOnlyHint=false, idempotentHint=false, destructiveHint=false, so the agent knows this is a non-idempotent mutation that is not destructive. The description adds only a vague note about models/ resolution and says nothing about whether the part is persisted to the active design, what happens on repeat calls, or what errors occur on a bad source path.

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?

It is a single short sentence with no padding, which is structurally efficient and front-loaded. However, brevity here reflects under-specification rather than tight editing, so it cannot score higher.

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 0% schema description coverage, no output schema, and only three bare annotations, the description is far too thin. An agent could not reliably call this tool from the definition alone.

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 0% across 5 parameters, so the description must carry the burden and it does not. It gestures at 'source' pulling a model from models/ but gives no syntax, and says nothing at all about name, role, placement_mm, or rotation_deg (units, expected tuple shape, 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?

The description is a sentence fragment with no verb: 'Assembly component and, if source is given, a model from models/.' An agent can infer this is about adding a part to an assembly, but the tool's actual action (add/create/link) and its effect on the design are never stated. It does not distinguish itself from siblings such as joint_create or import_cad_file.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives among the many siblings (joint_create, import_cad_file, inspect_part). The only conditional hint ('if source is given') describes a parameter, not a usage context.

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