measure_between

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

With no annotations, the description carries the full burden and does well: it discloses units (plate mm), the sign convention (negative axis gap = overlap along that axis), and that shared volume is only reported when objects overlap. It never explicitly states the operation is non-mutating, but 'measure' plus the read-only framing makes that clear enough.

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?

A single dense sentence that front-loads the core purpose before listing return values. Every clause carries information, though the parenthetical nesting makes it slightly harder to parse on first read.

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?

There is no output schema, so the description must describe the return values, and it does so thoroughly — minimum gap with location, center distance, per-axis box gaps, and overlap volume. Complete enough for an agent to call it and interpret results; only the interaction with measure_object remains unaddressed.

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%, so the description must compensate, and it does for the non-obvious parameters: it explains that part_a/part_b select sub-parts and that reusing the same object with two parts measures internal clearance. object_a/object_b are self-evident from their names; the only gap is part-name format or behavior on invalid part names.

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?

States a specific verb and resource — distance between two objects or two parts — and enumerates exactly which measurements are produced. It implicitly distinguishes itself from the sibling measure_object by requiring two operands, but never names that sibling or says so 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?

The parenthetical gives one concrete usage recipe: pass the same object twice with two different parts to get the clearance between them. Beyond that there is no guidance on when to prefer this over measure_object, or what preconditions (both objects on the same plate?) apply.

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