ui_diff_check

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

No annotations are provided, so the description carries the full burden. It explains the input ordering but gives no indication of the output format, return value, or side effects. The description only restates the comparison purpose without behavioral detail.

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, front-loaded sentence that efficiently conveys the main purpose. No wasted words, though it's arguably too sparse given the tool's complexity.

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 three required parameters and no output schema or annotations, the description omits crucial context: what the prompt is for, what the diff output looks like, and any prerequisites on image formats. It's minimal for an agent to invoke correctly.

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 explain parameters. It clarifies the role of expected_image_source and actual_image_source via 'first/second', but leaves prompt completely unexplained and doesn't specify what 'image_source' accepts (URL, path, etc.).

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's function: comparing expected vs actual UI for visual regression. It uses a specific verb and resource, and distinguishes itself from sibling image analysis tools by focusing on UI diffing.

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 phrase 'for visual regression' provides clear context for when to use this tool. It doesn't explicitly name alternatives or when-not-to-use, but the purpose is distinctive enough among siblings to imply appropriate usage.

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