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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false, so the safety profile is covered. The description adds useful context by specifying the source (US National Weather Service), geographic limitation to the US, and the active-status of alerts, but it does not disclose response shape, pagination, rate limits, or whether a coordinate or place name is required.

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 compact and front-loaded with the core purpose. It includes useful operational details like source, cost, and endpoint without excess. Minor redundancy exists between the title phrase 'Active weather alerts' and the description's 'Active NWS watches/warnings,' but it does not harm clarity.

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 tool with no output schema, the description is mostly adequate: it states the resource, source, and scope. The main gap is that the schema lists zero required parameters, yet the description implies a location is needed; it should clarify the requirement between q and lat/lon, and what to expect when both or neither are provided.

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%, so the parameters lat, lon, and q are already well documented with examples. The description contributes little to parameter meaning beyond saying the tool is for a 'US coordinate,' which aligns with lat/lon; the baseline of 3 is appropriate.

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 identifies the tool's resource as 'Active NWS watches/warnings for a US coordinate,' which goes beyond the title by adding the specific alert type, source, and geographic scope. It distinguishes itself from the sibling v1_weather by focusing on alerts rather than general weather, though it does not explicitly name that sibling.

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 implies usage: to retrieve active NWS watches/warnings for a location in the US, with 'US coordinate' hinting at lat/lon input. However, it does not explicitly state when to prefer this tool over v1_weather or mention any exclusions, prerequisites, or fallback logic.

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