foundry_measure_distance

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

The readOnlyHint annotation already indicates the operation is safe, but the description adds no additional behavioral context such as measurement units, Euclidean vs. grid distance, line-of-sight considerations, or the structure of the returned result. Since there is no output schema, the agent is left unaware of what the tool actually returns. The phrase 'points or tokens' hints at input modes but does not elaborate on behavior.

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, front-loaded sentence that efficiently conveys the core purpose. It is concise and to the point, with no wasted words. However, given the tool's complexity (11 parameters, no output schema), a slightly longer description that included essential usage hints would arguably be more appropriate, so it earns a 4 rather than a 5.

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?

The description is not complete enough for a tool with 11 parameters and no output schema. It lacks critical information about units, measurement type, how to specify points vs. tokens, the need for scene selection, and what is returned. The high parameter count and absence of parameter descriptions in the schema place a heavy burden on the description, which it fails to meet.

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 very low at 18%, with only userId and clientId having descriptions. The description does not explain the 11 parameters, such as how originX/Y vs originName/UUID relate to 'points or tokens,' whether sceneId is required, or how coordinates should be formatted. The mention of 'points or tokens' provides a minimal hint but falls far short of compensating 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's function with a specific verb and resource: 'Measure distance between two points or tokens.' This is immediately understandable and distinguishes it from sibling tools, which are primarily CRUD operations, canvas manipulation, and chat utilities. The wording is unambiguous and leaves no doubt about what the tool does.

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 clear context that the tool is for measuring distance, and there are no closely related sibling tools that perform measurement. However, it does not explicitly state when to use this tool over alternatives or provide any exclusions, which slightly prevents a perfect score. The intended use case is implicitly obvious from the purpose.

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