measure

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

No annotations are provided, so the description carries the behavioral disclosure burden. It describes what each kind returns: distance includes minimum distance plus nearest points, min_distance gives only a value, and angle is supported. It does not mention units or exact return shape, but for a simple read-only measurement tool this is reasonably 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 only two sentences and front-loads the operation, then concisely lists the supported kinds. Every sentence adds actionable information without repetition or 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?

Given that there is no output schema and no annotations, the description covers the essential usage path: entity source, allowed kinds, and what each kind returns. It could go further by specifying units or fully describing angle results, but it does not leave the agent guessing about the core behavior.

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 that entity_a and entity_b are handles from list_body_entities or tool output, and it gives concrete meaning to the 'kind' property. It still leaves angle output details somewhat underspecified, but the critical parameter semantics are provided.

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 uses a specific verb and resource: 'Measure between two entities using their handles.' It also lists the supported kinds ('distance', 'min_distance', 'angle'), which clearly distinguishes it from sibling inspection tools like bounding_box, volume, mass, or center_of_mass.

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 gives clear context for when to call this tool: any time the agent needs pairwise measurement between two entities. It even points to where entity handles can be obtained ('from list_body_entities or other tool returns'). It does not explicitly name alternatives or exclusions, but the 'between two entities' framing is sufficient guidance.

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