compare_cities

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

With no annotations, the description carries the full burden. It details the return value structure (dictionary with specific keys), which adds transparency. However, it does not disclose whether the operation is read-only, safe, or has any side effects. The behavioral traits beyond output are not fully addressed.

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 highly concise and well-structured. It front-loads the core purpose in the first line, then uses labeled sections for Args and Returns. Every sentence serves a purpose with no extraneous information.

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 an output schema, the description covers return values effectively. However, it could include more context about input validation (e.g., valid city identifiers, maximum number of cities) or prerequisites. Still, overall completeness is good.

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 description adds significant meaning beyond the input schema. It provides an example format (`['Bern', 'Thun']`), explains that 'None' means compare all available cities, and clarifies the parameter is optional. This compensates well for the 0% schema description 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 clearly states the tool's purpose: 'Compare multiple cities' and explicitly says it is 'the recommended tool for comparing one to many cities.' The verb 'compare' and resource 'cities' are specific, and the sibling tools (e.g., compare_cities_table) are differentiated by the description's emphasis on general comparison.

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 provides clear context on when to use this tool ('recommended tool for comparing one to many cities'), but it does not explicitly state when not to use it or name specific alternatives. However, this is sufficient guidance for an AI agent to differentiate from siblings.

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