measure_distance

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

With no annotations provided, the description must disclose behavioral traits, but it only states the operation without any details on return format, units, error handling, or side effects. It doesn't even explicitly confirm it's a read-only operation, though that's implied. The minimal information leaves the agent guessing about the tool's behavior beyond the basic action.

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 a single concise sentence that front-loads the purpose and immediately clarifies the parameter types. Every word earns its place, with no redundancy or unnecessary detail. It's an exemplary model of brevity.

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 simple tool, the description is still incomplete. It lacks any mention of the return value (presumably a number), units (e.g., meters), or how object names are resolved to coordinates. With no output schema and no annotations, the agent has to guess these details, making the description insufficient 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 schema has zero description coverage, so the description must clarify parameters. It does add meaning by stating that a and b can be object names or [x,y,z] coordinates, which explains the dual type in the schema. However, it doesn't elaborate on coordinate format, object name resolution, or units, so it only partially compensates for the lack of schema descriptions.

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 measures distance between two points, with a specific verb and resource. It distinguishes itself from sibling tools like get_bounding_box or ray_cast by focusing on direct distance measurement. However, it does not explicitly mention when to prefer this over alternatives, so it's clear but not fully differentiated.

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?

No guidance is provided on when to use this tool versus others. The description only states what it does, not the context or conditions under which it should be selected. There are no exclusions, prerequisites, or alternative suggestions, leaving the agent to infer usage.

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