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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows this is a safe, read-only operation. The description adds the real-time scope and return-field list, but it does not disclose behaviors like API key requirements, response format, or data source beyond the schema's param note about IATA/ICAO.

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 three sentences, front-loaded with the core purpose and inputs, and includes a concrete example. There is no redundant or filler content.

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 no output schema, the description lists the returned data fields, which is helpful for an agent to know what it will receive. Combined with robust schema coverage and safety annotations, the description is adequate for selecting and calling the tool, though units and response structure are not specified.

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 100%, with detailed parameter docs and an example already present. The description adds a condensed summary of location formats and a call example, but this is marginal beyond the schema's structured information.

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 uses a specific verb/resource ('Get current/real-time weather') and enumerates the data fields (temperature, condition, humidity, wind, UV, AQI), making it clear what the tool does. The 'current/real-time' qualifier distinguishes it from sibling tools like forecast or astronomy.

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 clearly states this is for current/real-time weather and provides supported location formats plus an example. It implicitly conveys when to use it versus forecast tools, but it does not explicitly name alternatives or state exclusions, so it falls just short of a top score.

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