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

With no annotations, the description carries the full burden, and it does add real context: the call is free and results are resolved to the city nearest the postal code rather than the exact location. It omits failure behavior for invalid or unmatched postal codes and any caching/rate-limit notes.

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?

One sentence plus a pricing flag, front-loaded with the cost differentiator and then the scope. No filler.

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 read tool with no output schema, the description covers what is returned, the source, and the geocoding behavior. Only edge-case behavior (invalid postal code) is left unstated.

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 single parameter has 0% schema description coverage, but the description explains its semantics — it is a postal code used to find the nearest city, implying approximate rather than exact geolocation. It doesn't state accepted formats or country assumptions, which matters for a postal-code input.

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 concrete resource (current conditions plus the next 3 forecast periods), the data source (Environment Canada), and the geographic resolution (city nearest a postal code). The explicit 'next 3 forecast periods' scope implicitly separates it from forecast_full, though no sibling is named.

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 statement of when to use this versus forecast_full or sites_forecast, nor any prerequisite or exclusion. The limited 3-period scope hints at the tradeoff but the agent must infer it.

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