get_comparables

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It lists the computed metrics and mentions 'methodology,' but does not disclose read-only behavior, error conditions, or what happens if both listing_id and spec are provided. It covers the main output but lacks depth on edge cases and side effects.

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, well-structured sentence that front-loads the primary purpose and lists key output metrics, followed by a clear usage instruction. Every part earns its place with zero redundancy.

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?

With 13 parameters, no required fields, no annotations, and 8% schema coverage, the description is far too brief. It does not explain the two invocation modes in detail, the relationship between parameters, or how to interpret the output (though an output schema exists). An agent would struggle to correctly assemble a 'vehicle spec' or know when to use which mode. More guidance is needed for correct invocation.

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 description coverage is only 8% (only price_cad has a description). The description says 'Pass a listing_id OR a vehicle spec' but does not clarify which of the 13 parameters constitute a 'spec' or how they interact. It adds minimal semantic value beyond the schema names, leaving the agent to guess which fields are required for spec mode. This is a significant gap given the low schema 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 states a clear purpose: 'Comparable-price analysis' with a list of specific outputs (sample size, median/mean/quartiles, mileage-adjusted median, premiums, subject percentile). This distinguishes it from generic search tools, but it does not explicitly name a sibling it is not (e.g., compare_cars or analyze_market). The resource and verb are clear, but the differentiation is implicit.

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 gives a direct usage instruction: 'Pass a listing_id OR a vehicle spec.' This tells the agent how to invoke it and implies the two modes. However, it does not provide when-not-to-use guidance or mention alternatives, so the guidance is clear but not comprehensive.

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