compare_images

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

No annotations provided, but the description details both modes (side_by_side layout, difference formula with visual result) and the amplify parameter effect. Does not explicitly state it is read-only but implies it.

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?

Front-loaded with purpose, uses bullet-like structure. Somewhat lengthy but each part adds value; could tighten file parameter explanation.

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 no annotations, no output schema, and 6 parameters, the description covers key behavioral details (mode, amplify, use case) but omits file parameter semantics and return value information, leaving 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 0%, so description must compensate. Explains mode and amplify well (2 of 6 parameters), but leaves filename_a, filename_b, subfolder_a, subfolder_b undocumented. Partial coverage.

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 compares two images ('See what changed between two passes') and ties it to a loop step, distinguishing it from siblings like image_diff_stats (numerical stats) and get_image (retrieve).

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?

Provides practical guidance: use every pass against your best-so-far, and explains when to use each mode. Lacks explicit when-not-to-use or alternative tools, but context is strong.

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