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

Beyond the annotations, the description adds critical operational context: authentication via x-api-key, a free key source at POST /api/keys, and the fact that this tool consumes daily quota while aggregate tools do not. It also makes clear the call is live and geographically scoped.

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 two dense sentences with zero filler. The core action and location scoping are front-loaded, followed by the essential authentication, quota, and sibling reference details.

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 live read-only tool with no output schema and fully described parameters, the definition covers authentication, quota impact, geographic scope, and how to find valid signal ids. The only notable gap is that it does not describe what a live signal run returns, which would help an agent interpret the result.

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?

With 100% schema description coverage, the schema already documents lat, lng, and signal. The description adds value by restricting the point to Colorado or Virginia and giving an example signal id, but it does not add further meaning beyond that geographic constraint.

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 states a specific verb and resource: running one proven signal adapter live at a point in Colorado or Virginia. It also differentiates from siblings by pointing to list_signals for ids and contrasting with aggregate tools, so an agent can distinguish its role immediately.

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?

It clearly says to see list_signals for valid signal ids and notes that aggregate tools do not count against the daily quota, implying when to choose this live single-point tool over aggregates. The guidance is strong, though it does not explicitly state when not to use it beyond the aggregate contrast.

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