center_of_mass

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

No annotations exist, so the description must carry the behavior disclosure burden. It does clarify coordinate system and units, but it does not disclose return shape for multiple bodies, whether the tool is read-only, or what happens with invalid/missing body names. This is useful but not fully transparent.

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 one short sentence that immediately front-loads the action (`Return center of mass`) and includes every necessary clue without wasting words. There is no filler or repetition.

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?

With only one optional parameter and no output schema, this description is nearly complete. However, the phrase `for a body or all bodies` is ambiguous as to whether the tool returns a single combined center of mass for all bodies or a collection of centers. It also does not describe the returned vector shape (e.g., x, y, z). Lacking that makes it not fully complete.

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 is the only meaningful note about parameters. The single parameter, `body_name`, is semantically explained by `for a body or all bodies` (implicitly null/omitted means all, provided string means a specific body), adding relevant meaning beyond the plain schema.

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 states a specific action (`Return center of mass`), identifies the resource (`body` or `all bodies`), and adds useful details (`mm`, `world coordinates`) to disambiguate from sibling tools like `mass`, `bounding_box`, and `volume`.

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 `for a body or all bodies` provides context about scope, but there is no explicit guidance on when to choose this tool instead of alternative measure tools, no prerequisites, and no exclusions for cases when the body name may not exist or the assembly is not fully grounded.

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