compare_cars

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

Annotations are absent, so the description carries the full burden. The description indicates a read-only comparison operation (no side effects mentioned), but it does not disclose important behavioral details such as whether it requires specific authentication, whether there are rate limits, or how the output schema is structured (though an output schema exists). It also does not mention that the comparison is based on current data, which could be inferred. This is adequate but not rich.

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 one sentence, concise, and front-loads the core purpose. It lists key output categories efficiently. A small deduction because it could specify the need for at least two IDs (but that's in schema) and could be slightly more structured (e.g., bullets), but it's effective.

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 a moderate complexity (2 params, one optional), an output schema exists, and sibling tools provide context (like analyze_listing, score_listing), the description is fairly complete. It mentions the main output categories. It doesn't explain edge cases like what happens if some IDs are invalid, but that might be minor. It also doesn't state that the comparison is based on current data or that it may be heavy operation. But overall, adequate.

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 schema has 100% description coverage for parameters: listing_ids has clear description (2-10 ids to compare), and profile has a default and a list of named profiles with a custom dict format. The description adds little beyond the schema, but because coverage is high, the schema handles parameter documentation. The description does not need to repeat schema details, so a baseline of 3 is exceeded slightly because it hints at profiling ('project score'), implying the profile parameter's role.

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 verb 'compare' and the resource 'several listings', and lists specific outputs (key facts, comps position, project score, deal signals, description risk flags). It distinguishes itself from siblings like analyze_listing (which likely analyzes a single listing) and score_listing (likely scores a single listing). However, it does not explicitly contrast with siblings, so a slight deduction.

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 usage when an agent wants to compare multiple listings side by side, and the purpose is clear. But it does not explicitly state when not to use it (e.g., for single-listing analysis, use analyze_listing or score_listing). Given the tool name and description, context is clear enough, but explicit exclusions would earn a 5.

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