object_measure

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

The annotations already declare readOnlyHint=true, and the description reinforces this with 'Side-effects: None' and 'Read-only measurement query.' It adds useful behavioral context by stating that results are deterministic and type-specific, though it does not describe backend support limitations or failure conditions.

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 short, front-loaded, and structured into purpose, side effects, and disambiguation. Every line contributes to selecting or safely invoking the tool.

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 read-only, single-parameter tool with an output schema and readOnlyHint annotation, the description is largely complete. The main remaining gap is sibling routing: it does not explicitly distinguish measurement from object inspection or extents queries.

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 100%, so the single object_id parameter is already fully documented in the schema. The description does not add further meaning about accepted identifiers, resolution behavior, or lookup semantics beyond what the schema 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 states a specific verb and resource: measure one object. It also defines the output scope as type-specific metrics plus a WCS bounding box, which is clearer than a generic object inspection tool. However, it does not explicitly name sibling alternatives such as object_get, solid_inspect, or drawing_extents.

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 'Read-only measurement query' implies the use case, and 'Disambiguation' suggests it is for deterministic mathematical metrics. But there is no explicit guidance on when to choose this tool versus object_get, solid_inspect, drawing_extents, or object_intersections.

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