compare_moles

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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering safety and open-world assumptions. The description adds valuable behavioral context by stating 'Reports observed differences only — not a diagnosis', clarifying that the output is limited to observed differences and does not provide medical judgment. This goes beyond the annotations and sets proper expectations for the agent.

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 two sentences with no redundancy. It front-loads the action ('Compare two recorded mole photos') and immediately adds the key limitation ('not a diagnosis'). Every word earns its place, making it highly efficient.

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?

The tool is relatively simple, and the schema covers all parameters. However, since there is no output schema, the description only vaguely mentions 'Reports observed differences' without specifying the output format (e.g., list of changes, textual summary). It also does not differentiate from the sibling get_mole_changes, which could lead to ambiguous tool selection. While the core purpose is clear, these gaps prevent a higher score.

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%, and each parameter already has a clear description (e.g., imageId1 'First image ID (older)', imageId2 'Second image ID (newer)'). The tool description adds no additional parameter semantics, so the baseline score of 3 applies.

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: 'Compare two recorded mole photos' – a specific verb and resource. It also distinguishes itself from diagnostic tools by noting 'not a diagnosis', which differentiates it from siblings like classify_lesion_features or assess_risk_from_factors. This makes the tool's purpose unambiguous.

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 implies the usage context (comparing two photos of a mole) but does not explicitly mention when to use this tool versus alternatives like get_mole_changes, which might also track differences over time. There is no mention of exclusions or alternative routing, leaving the agent to infer the appropriate scenario.

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