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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior, so the description needn't restate safety. It adds genuinely new context: the default value of 'detail' (address), the quota impact ('One call counts as one geocoding request'), and where to look for the result shape. It does not say what happens when no address exists at the point, which is the main remaining gap.

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?

Front-loaded with the one-line purpose, then the parameter semantics, then the result/cost notes — every sentence carries information an agent would otherwise have to infer. No repetition of the title or annotations.

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?

With no output schema, the description compensates by pointing to geocode's fields and by covering the enum semantics, default, and request cost. Edge-case behavior (unresolvable points, partial matches, error responses) is the only notable omission for a lookup tool of this complexity.

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%, so baseline is 3, but the description earns more by explaining the containment hierarchy behind the 'detail' enum and disclosing its default, neither of which the schema states ('what to return' is all it says). The 'language' parameter is left entirely to the schema, keeping it short of a 5.

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 specific verb and resource ('Finds the address or place at a point') and names the operation class ('reverse geocoding'), which immediately separates it from the sibling geocode tool that goes the other direction. An agent can select it without opening the schema.

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?

The description explains the selection logic for the 'detail' parameter in plain terms (nearest address/object, then progressively larger containing units), which tells the agent when to pick each mode. It references geocode only for output-field parity rather than as an explicit alternative, so the when-not-to-use guidance is implied rather than stated.

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