compare_sites

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

Annotations already indicate readOnlyHint=true, so the tool is safe. The description adds value by detailing the return structure (sites array with fields, winner object, decision_rationale) and the decision-making process. No contradictions with annotations.

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 well-structured: purpose first, then example, parameter details, and sibling exclusions. It is slightly verbose but each sentence adds value. Could be more concise by removing redundant phrasing, but overall 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 no output schema, the description adequately covers the return fields and decision logic. It explains the context of use (candidate parcels, factors) and provides an example. However, it does not explain the meaning of each return field (e.g., composite_score scale, water_stress_score interpretation), which could be helpful.

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 only one parameter (locations) with no description. The description adds format (semicolon-separated lat,lon), constraints (2-4 max), and mentions capacity_mw in the example and param list, but capacity_mw is not in the schema. This inconsistency reduces clarity. Schema coverage is 0%, so the description partially compensates.

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 purpose: comparing 2-4 candidate parcels for site selection. It specifies the factors considered (grid, fiber, water, tax, climate) and distinguishes from sibling tools by explicitly saying when not to use it (single site: analyze_site, market ranking: rank_markets).

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 explicit when-to-use (narrowed to 2-4 parcels, side-by-side comparison) and when-not-to-use (single site, market ranking). Includes an example query with expected response structure, and names alternatives.

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