renforge_diff_screenshots

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

With no annotations, the description carries the full burden of behavioral disclosure. It explains the input behavior (saved PNGs, empty after_path) and the output (bounding box). However, it does not disclose the behavior of the threshold parameter or whether the tool has side effects, leaving some gaps.

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 three sentences with purpose, parameter explanation, and use cases. It is compact, front-loaded, and every sentence adds value.

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?

An output schema exists so return values don't need explanation, but the description omits project_path and threshold semantics, which are essential for correct invocation. The main diffing behavior is clear, but the parameter gaps prevent full completeness.

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 description explains before_path and after_path, but ignores project_path (a required string) and threshold (an integer with default). Since schema coverage is 0%, the description fails to compensate for half the parameters, especially the required project_path.

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 clearly states the tool diffs two frames and returns the bounding box of what changed, using specific verbs and resources. This distinguishes it from sibling tools like screenshot capture or image search.

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 explicit use cases ("measure how far an element moved or to confirm a tweak left everything else untouched") and explains how to use the after_path parameter (empty to diff against current live frame). It does not explicitly exclude alternatives, but the contexts are clear enough.

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