measure_gap

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

No annotations are provided, so the description carries the full behavioral burden, and it discloses almost nothing. It implies a read-only measurement but does not state the units, the coordinate space, whether the result is a single scalar or a pair of offsets, or whether any page/element state must exist first.

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?

One short sentence, front-loaded and free of padding, but it is a fragment rather than a sentence and is under-specified rather than genuinely concise. Nothing is wasted, but too little is said.

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 annotations, no output schema, and no parameters, the description is the only source of information, and it omits the return type entirely. For a measurement tool whose whole value is the number it produces, this is a significant 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?

The input schema is an empty object with zero parameters, which is the baseline-4 case per the rubric. The description does describe the conceptual operands ('a puzzle piece and its slot'), adding a little meaning, though the tool takes no arguments at all.

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 names the thing being computed ('the distance between two elements') and hints at the domain ('puzzle piece and its slot'), which is more than the bare name gives. But it is a noun phrase with no verb and no scope qualifier, and it never says how it differs from its close siblings measure_frames and measure_rotation.

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 call this tool, no prerequisites, and no mention of alternatives. The sibling set contains two other measurement tools, and the description provides nothing to help an agent choose between them.

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