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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, and the description merely echoes the passive 'measure' framing without adding anything. It says nothing about how tolerance affects the result, how mismatches are reported, or what happens when no pairs are given, all of which matter for a 5-parameter geometric check with no output schema.

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?

It is a single front-loaded sentence with no filler, which is good structurally. But one sentence is undersized relative to a tool with five parameters, two of them nested object arrays, so the brevity reads as under-specification rather than economy.

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?

Rich annotations cover the safety profile, but nothing covers the calling contract: five complex parameters with zero schema documentation and no output schema mean the agent cannot tell what to pass or what result to expect. The description does not fill that gap.

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%: pairs, artboard, tolerance, attachments, and display_width are all undocumented in the schema, and the description explains none of them. The nested 'expect' enum (overlap/touch/clear) and 'into'/'end' attachment fields are especially opaque and untouched by the description.

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 verb 'measure' and the notion of parts touching give a rough idea, but 'parts' and 'what they belong to' are undefined and the description never names the actual objects (shapes, pairs, attachments) the schema exposes. It does not distinguish this from spatial siblings like align, inspect_layout, or resolve_overflow.

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?

There is no statement of when to use this versus alternatives such as align, snap_to_grid, or inspect_layout, and no prerequisites or exclusions. An agent must infer the use case entirely from the name.

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