open_assembly

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

With no annotations, the description carries the full disclosure burden and does so well: it names the side effect (the file becomes the current document), the post-import state (parts arrive as components at their places), the return value (component count), and the refusal behavior for single-part files. It stops short of error/permission behavior or what happens to a previously open document, 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?

Three sentences, front-loaded with the primary action and file formats, followed by import semantics and the exclusion rule. Every sentence carries information; the only mild looseness is the semicolon-clause structure, but nothing is wasted.

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 one-parameter open tool with no annotations and no output schema, the description supplies the return value (component count), the side effect on document state, and the alternative tool. That is close to complete; only edge-case error handling is absent.

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% and the single 'path' parameter is undocumented in the schema. The description partially compensates by naming accepted file formats, which tells the agent what kind of path is valid, but adds no syntax, extension-vs-directory, or resolution detail beyond that.

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 gives a specific verb (open/import) plus resource (assembly), enumerates the accepted file formats (.sldasm, STEP, IGES, Parasolid), and explicitly distinguishes itself from open_part by noting that single-part files are refused. An agent can route between open_assembly and open_part without opening either schema.

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?

It states when to use it (assemblies) and when not to (files holding a single part), naming the alternative tool (open_part) with the selecting condition. It also hints at follow-on tools (list_components, add_mate), which further anchors intended usage.

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