Get Bounding Box

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds valuable behavioral details: the return of min, max, size, and center in cm (Fusion internal units), and the specific behavior for components (unions bounding boxes of all contained bodies). This goes beyond the annotations without contradicting them.

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 three sentences with no redundancy. The first sentence front-loads the core purpose and return values, the second adds a key behavioral nuance, and the third gives a practical use case. Every sentence earns its place, and it is appropriately sized for the tool's simplicity.

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?

Given the tool's low complexity (one parameter, no output schema), the description is complete: it explains what is returned, the units, component behavior, and a typical use case. Annotations cover safety, and the schema covers the parameter. Nothing critical is missing for correct invocation.

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?

The input schema has 100% coverage: the 'name' parameter is described as 'Body or component name'. The tool description reinforces that by saying 'by name' but does not add new semantic meaning beyond the schema. The component behavior is not parameter-specific, so the description adds no extra value to parameter understanding beyond what the schema already provides.

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 clearly states the tool's action ('Axis-aligned bounding box') and resource ('body or component by name'), and lists the returned fields (min, max, size, center). It does not explicitly name a sibling tool for comparison, but the specific concept of a bounding box distinguishes it from other measurement tools like get_physical_properties or measure_distance. The purpose is unambiguous and not a tautology.

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 provides a usage context ('Useful for measuring imported reference geometry') but does not explicitly state when to use this tool over alternatives, nor does it mention exclusions or prerequisites. It implies a scenario but leaves the agent to infer selection criteria without direct guidance on sibling tools.

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