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

Beyond the readOnly/openWorld/idempotent annotations, the description adds valuable behavioral details: '60s cache,' 'US Government public domain,' 'US-only coverage,' and the list of returned fields. This transparently discloses data source, caching, and geographic scope, with no contradiction to 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 concise and front-loaded: purpose first, then return fields, then cache/coverage, and finally use case. Every sentence adds value, especially the return field list which is necessary given no output schema. No wasted words.

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 tool with 6 optional parameters and no output schema, the description covers all essential aspects: filters, return fields, caching, geographic limitation, and use case. It is self-sufficient for an agent to decide when and how to use it, and it complements the schema and annotations well.

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% (all 6 parameters have descriptions), so the baseline is 3. The description largely echoes the schema (e.g., '2-letter state code,' 'exact NWS event name') without adding meaningful extra semantics beyond summarization. It doesn't elaborate on interplay or edge cases.

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 it 'Fetches active alerts from api.weather.gov' with specific filters (area, event, severity, urgency, status), making the tool's function unambiguous and distinct from sibling climate tools like earthquakes. It also lists the exact return fields, reinforcing purpose.

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 clear context for when to use it: 'Use for situational awareness on active weather hazards.' This gives a strong usage context, though it does not explicitly mention when not to use it or alternatives. Since it doesn't exclude any alternatives, it falls just short of a 5.

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