renforge_measure

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

No annotations are present, so the description carries the full burden. It discloses that the tool returns 'actionable deltas in logical pixels', adds a 'pass' verdict when tolerance is given, samples the live frame for contrast, and resolves node IDs live. This is highly transparent about behavior and edge cases (one vs two targets for contrast).

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 appropriately sized and front-loaded with the core purpose in the first sentence. The supporting details about actions and target formats are dense but well-organized, with every sentence adding necessary value. No filler or redundancy.

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?

Given the tool's complexity (5 parameters, 6+ actions, special contrast behavior), the description covers the critical aspects: action meanings, target resolution, tolerance semantics, and contrast's live-frame WCAG ratio. It does not explain 'project_path', but that is a standard parameter across sibling tools. The output schema exists, so return structure details are not required in the description.

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 has 0% description coverage, so the description fully compensates. It explains the 'action' enum values, defines 'targets' and 'within' as either node IDs or bounds objects, and clarifies that 'tolerance' produces a pass verdict. This goes well beyond the bare schema, which only lists names and types.

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 uses a specific verb ('measure') and clear resource ('pixel relationships between scene nodes'), and lists the exact actions supported (align, gap, distribute, center, overlap, fit, contrast). This distinguishes it from sibling tools like renforge_get_displayable_bounds or renforge_position_element, which focus on single-element bounds or positioning.

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 description provides clear context on when to use the tool: whenever you need to measure alignment, gaps, distribution, centering, overlap, fit, or contrast between scene nodes. It explains the target format and tolerance behavior, but does not explicitly mention alternatives or exclusions, so it lacks the direct 'use X instead' guidance seen in the highest-caliber descriptions.

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