combine_bodies

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

No annotations are provided, so the description carries the full behavioral burden. It usefully discloses operation outcomes and the return value ('mass properties and the bodies left'), but it does not state whether the operation mutates or consumes source bodies, permission requirements, or reversibility.

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 front-loaded with the core action and resource, then efficiently explains operation modes and defaults. Every sentence contributes necessary invocation context with no filler.

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 4-parameter tool with no annotations, no output schema, and no schema descriptions, the description is largely complete: it covers purpose, operation semantics, parameter meaning for three of four parameters, and return content. It omits the `name` parameter and mutation/safety context.

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 explains `main` as a `list_bodies` name, defines operation values (`add`, `subtract`, `common`), and clarifies `tools` as body names defaulting to every other body. The `name` parameter is left undocumented, preventing a perfect score.

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: combines solid bodies into `main`. It also defines the three operation modes (`add`, `subtract`, `common`), making the tool's core purpose unambiguous and distinct from sibling body operations like `split_body`.

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 description explains what each operation does and that `tools` defaults to every other body, which implies usage for combining bodies. However, it does not explicitly say when to use this tool versus alternatives such as `split_body` or when to avoid it.

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