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

With no annotations, the description must carry the full behavioral burden. It only reveals the external provider (Open-Meteo) and does not mention network dependence, approximate results, error behavior, output format, or that most schema parameters appear unrelated and may be ignored or discarded.

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 single sentence is front-loaded with the core output and has no filler, so it earns its place. It is slightly too terse to be a 5 because it omits necessary invocation context.

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?

Given 9 optional parameters, a mismatched schema, absent annotations, and no output schema, this one-line description is far from complete. An agent cannot determine which parameter to pass or what the returned coordinates will look like.

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 the schema documents all 9 parameters, the description adds no mapping from any parameter to the place being geocoded. The only plausible candidate, 'city', is described as 'for a public weather hint; discarded after the call', which actively conflicts with the tool's stated geo purpose.

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 clearly identifies the tool's output as latitude and longitude for a place, backed by Open-Meteo, which is specific enough to convey the core geocoding function. It does not name sibling alternatives or clarify how the place is supplied, so it stops short of 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?

No guidance is given about when to prefer this tool over siblings like weather-hint or iana-zones, and no exclusions, preconditions, or alternative routing are described. The only implied usage is 'need coordinates,' but the description never states how to select the place or what to do when multiple matches exist.

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