compare_citiesRetrieve current weather side by side for 2-5 cities, naming the warmest and coldest.
Current weather side by side for 2-5 cities, with the warmest and coldest named.
| Name | Required | Description | Default |
|---|---|---|---|
| cities | Yes | Two to five city names |
| Name | Required | Description | Default |
|---|---|---|---|
| cities | Yes | ||
| coldest | Yes | ||
| warmest | Yes | ||
| spread_c | Yes | Warmest minus coldest current temperature |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare read-only, open-world, and idempotent behavior, so the description only needs added context. It usefully discloses that results are presented side by side and that the warmest and coldest cities are named, though it does not describe failure behavior for invalid cities.
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?
A single efficient sentence with the key scope and output framing front-loaded. Every phrase contributes useful 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?
For a simple read-only comparison tool, the description covers purpose, input range, and notable output behavior. Output schema, parameter schema, and annotations already supply the remaining structured details.
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 the cities parameter already documents the 2-5 item constraint. The description reinforces the same range but adds no new format or syntax guidance beyond the schema.
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?
States a specific action and resource: current weather compared side by side for 2-5 cities. The multi-city comparison scope clearly distinguishes it from single-current and forecast siblings.
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?
Strong implied usage for comparing current weather across multiple cities, with the 2-5 city range making the applicable scenario clear. It does not explicitly say when to choose this over get_current or get_forecast, so it stops short of full alternative guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.