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

No annotations are provided, so the description carries the burden, and it discloses several traits: free access, active-only alerts, Environment Canada as the source, first-three-character postal-code matching, and a top-3 result limit. It still omits return format and error or rate-limit behavior, keeping it from a 5.

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 compact sentence front-loads cost, source, alert types, geographic scope, truncation behavior, and result limit. There is no filler beyond the useful 'FREE' cost signal.

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 one-parameter lookup, the description covers what is returned and the top-3 limit, but because there is no output schema it does not describe the response structure or empty/error cases. It is adequate but incomplete.

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 0% and only says postal_code is a string, but the description adds that it must be a Canadian postal code and only the first 3 characters are used. This meaningfully compensates for the undocumented parameter, though it leaves some ambiguity about whether full postal codes are accepted and truncated.

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 that the tool returns active Environment Canada warnings, watches, and advisories near a Canadian postal code and caps results at the top 3, so the resource and scope are clear. It does not explicitly explain how it differs from sibling area_alerts, so it is not a 5.

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?

There is no explicit when-to-use or when-not-to-use guidance, and sibling area_alerts is not mentioned. Usage is only implied by the postal-code scope, leaving the agent without a routing rule.

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