start_assembly_operation

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

With no annotations, the description carries the full burden and does well: it discloses idempotency semantics (same request_id + different args fails), retention window tied to addon history, and lifecycle (survives MCP restart but not FreeCAD exit). It does not mention permissions, rate limits, or what happens to a partially completed job on FreeCAD exit, which keeps it from a 5.

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 retry/idempotency guidance and the return-and-poll instruction are front-loaded, and every sentence carries information. The fragmentary, telegraphic style ('No arbitrary Python.', 'Returns job_id; poll get_assembly_job.') is dense but readable.

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 an async submit tool with no output schema, the description covers the return value (job_id), the polling path, and job lifetime, which is what an agent needs to drive the workflow. The remaining hole is the shape of the 'arguments' payload, which neither schema nor description supplies.

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%, so the description must compensate. It thoroughly explains request_id (idempotency key semantics, mismatch failure) and points to where valid operation values come from, but the required 'arguments' object is left entirely unexplained despite being a free-form nested object whose shape presumably depends on the operation.

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?

Opens with a specific verb+resource: 'Submit a native CAD job immediately'. It also distinguishes itself from the code-execution siblings by stating 'No arbitrary Python', and from synchronous tools by saying to use it for long operations. Slightly indirect in that the primary action is described via its async behavior rather than naming the assembly operation explicitly.

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 conditions: use for long operations instead of blocking on a tool call, and consult get_assembly_capabilities for the allowed operation set. It sets a real exclusion ('No arbitrary Python'), though it never states when a synchronous sibling would be preferable or what happens if the operation name is invalid.

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