measure

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds a genuine behavioral detail beyond the annotations – that output Notes may report 'scale not applied' or 'negative scale' – but does not cover invalid names, empty arrays, or cost. Useful incremental context against a low bar.

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?

Dense but efficient: the return fields are front-loaded, followed by usage and the alternative. Every clause carries information and there is no filler, though the opening field list reads as a run-on.

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?

With no output schema, the description does the right thing by enumerating the returned fields, which largely covers the return contract. However, it says nothing about the required 'names' input, and for a tool an agent is told to call after every move, that input contract should be stated.

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% and the single parameter 'names' is a bare array of strings with no description. The description never explains what 'names' refers to (object names? scene paths?), so it fails to compensate for the coverage gap; only the phrase 'after every move' hints at the input.

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 enumerates the exact quantities returned (world-space size, min/max, center, origin position and its normalized coordinates, rotation, scale), so an agent can tell this is a per-object measurement query. The verb is implied by the name 'measure' rather than stated, but the scope is unambiguous and it distinguishes itself from measure_profile explicitly.

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 a concrete trigger ('Use it after every move') and names the alternative for a common adjacent case ('Use measure_profile to measure a reference image instead of an object'). No explicit when-not beyond that one alternative, but the routing condition is clear.

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