Visual Diff (AI) [Pro]

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

No annotations provided, so description carries full burden. Discloses Pro feature, input format (base64 PNG), behavior (captures current screen as after), and output (list of changes with descriptions and regions). Fully transparent without contradiction.

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?

Two sentences, front-loaded with purpose and key details. No waste.

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 2 params, no output schema, and no annotations, description covers everything needed: what it does, how to use it, input format, output format. No gaps.

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 coverage is 100%, description adds value by explaining usage context: before_screenshot is base64 PNG of previous screen state, and tool captures current screen automatically. Goes beyond schema descriptions by clarifying the 'after' image is captured by the tool.

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?

Clearly states it compares current screen with a previous screenshot to identify what changed. Provides specific verb 'compares' and resource 'screenshot', and distinguishes from siblings like take_screenshot and verify_screen by focusing on 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?

Explicitly says to provide a base64 PNG screenshot as the 'before' image, and that the tool captures the current screen as the 'after' image. Also includes 'Useful for verifying that an action had the expected effect', giving clear context for when to use.

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