vision.compare

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

No annotations are provided, so the description must fully disclose behavioral traits. It mentions 'compare' which implies a read operation, but it does not state whether the tool is read-only, whether it modifies state, what happens on mismatch, or any side effects. This lack of transparency is a significant gap.

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 a single sentence, making it concise and front-loaded. However, it is so minimal that it may under-specify the tool's behavior. Every word is necessary but not sufficient for full understanding.

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 has 3 required parameters, no enums, and an output schema (unknown content), the description does not address what the output looks like (e.g., diff, boolean, score) or any other contextual details like error handling or trivial case behavior. The description is incomplete for a tool of this complexity.

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, and the description adds minimal parameter meaning. It refers to 'two captures' (matching capture_a and capture_b) but does not explain their format, constraints, or how 'project_path' is used. The description does not compensate for the missing parameter documentation.

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 action is 'Compare two captures' and specifies the basis ('by digest identity and overview metadata'). It distinguishes the tool from siblings like 'vision.verify' or 'vision.query' by focusing on comparison of captures. However, it doesn't elaborate on what the comparison yields, which could be clearer.

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?

No guidance is provided on when to use this tool versus alternatives such as 'vision.verify' or 'vision.observe'. The description does not mention prerequisites, context, or exclusions, leaving the agent without direction for tool selection.

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