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

Annotations already convey read-only, idempotent, non-destructive behavior. The description adds valuable context beyond those annotations: include_geometry=true triggers large payloads, empty results mean no active activity, and features carry kind/name/intensity/timing properties. This enriches the agent's mental model of what the tool will do and return.

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 packs the resource, content taxonomy, behavior caveats, empty-result semantics, sibling pointer, and an example into four dense sentences with no fluff. Every sentence earns its place and the most important information is front-loaded.

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 tool with one optional parameter and an existing output schema, the description covers all essential decision points: what is returned, how to enlarge geometries, what an empty result means, and where to find a specific related type of data. Nothing needed for correct invocation is missing.

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 100% for the single boolean parameter, so the baseline is 3. The description adds a performance caveat (large geometries) and a concrete example invocation, which slightly exceeds what the schema alone provides. The schema already explains the parameter, so the extra value is modest but real.

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 uses a specific verb ('Get') and resource ('Active NHC tropical systems') and clearly enumerates the returned content: forecast cones, track lines, forecast points, watches/warnings, and outlook areas. It also names the sibling tool for reconnaissance data, distinguishing itself without needing to inspect other schemas.

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 explicitly defines its scope (Atlantic + East Pacific, active systems) and gives an exclusion: 'Aircraft reconnaissance fixes and flight-level observations are in get_tropical_observations.' This tells the agent when to choose this tool and when to prefer a sibling. The empty-result interpretation further clarifies the expected output in valid usage.

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