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

Without annotations, the description carries the burden of explaining behavior, but it only states the output type and omits critical details such as which input parameter is actually used and that most parameters are ignored. The city parameter description even misleadingly says it is 'discarded after the call'.

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 a single concise sentence with no unnecessary words, making it easy to parse and understand at a glance.

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?

The tool has 9 optional parameters and no output schema, yet the description does not explain which parameter to provide or what the returned coordinates look like. This leaves the agent without enough context to invoke the tool 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?

Although every parameter has a description, the descriptions are largely irrelevant or contradictory to the tool's purpose. For example, the city parameter is described as 'for a public weather hint; discarded after the call', which does not clarify how it is used for geocoding, and several parameters (ref, feed, json, path, etc.) have no connection to latitude/longitude.

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 'Latitude and longitude for a place via Open-Meteo' clearly identifies the tool's core purpose of returning geographic coordinates for a location, and it is distinct from sibling tools like weather-hint or timezone.

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?

No guidance is given on when to use this tool versus alternatives, nor are any prerequisites or typical invocation scenarios mentioned.

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