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

With no annotations, the description carries the full burden and does disclose two genuinely non-obvious behaviors: results are capped at the top 3 by severity, and only currently active alerts are returned. It does not cover authentication, rate limits, or what an empty response looks like, but the truncation disclosure is the critical piece an agent would otherwise get wrong.

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 fragment plus one sentence, with the cost marker and the resource front-loaded and the severity cap placed last where it reads as a qualifier. Nothing is wasted and nothing is buried.

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 one-parameter, read-only lookup with no output schema and no annotations, the description covers what it fetches, the geographic scope, the alert categories, and the result cap. That is everything an agent needs to decide to call it and to interpret a short result set correctly.

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 schema gives the single 'zip' string parameter no description at all (0% coverage), so the description must compensate; it specifies 'US ZIP code', telling the agent the expected locale and identifier type. It stops short of stating the format (5-digit vs ZIP+4) or how to handle non-US or invalid inputs.

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 resource (active National Weather Service alerts, with the alert types named) and a specific scope (a US ZIP code, top 3 by severity). It is clearly distinguishable in spirit from state_alerts, but it never names or contrasts with that sibling, which keeps it out of the top band.

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?

Usage is only implied: 'for a US ZIP code' suggests this is the ZIP-based path while state_alerts is presumably the state-based path, but the description never states when to prefer one over the other or any exclusions. The 'FREE' marker hints at a cost trade-off but is not framed as guidance.

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