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

Annotations already cover read-only, idempotent, non-destructive semantics and closed-world scope, yet the description adds genuinely new operational context: it consumes one address lookup against the account's monthly cap, and inherits the same storage/attribution terms as geocode. It does not cover failure behavior (e.g., open ocean / no match) or result format.

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?

Three short sentences, front-loaded with what the tool does, then cost, then licensing. Every sentence carries distinct information with no redundancy or filler.

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 should say something about what comes back (an address record? multiple candidates when limit > 1? what happens when nothing is found). It also leaves the lang/limit interaction with results unexplained, so an agent knows how to call it but not fully what to expect.

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 description coverage is 100%, so lat, lon, lang, and limit are fully documented in the schema with ranges, defaults, and formats. The description adds no meaning beyond that, so the baseline of 3 applies.

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 ('Find the nearest address or place to a latitude/longitude') plus the data source (OpenStreetMap). The reverse direction is clear enough to distinguish it from the forward 'geocode' sibling, though the description never names that sibling to make the contrast explicit.

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?

Usage is implied by 'reverse' vs the sibling 'geocode', but there is no explicit 'use this when you have coordinates; use geocode when you have an address' routing statement. The only sibling reference ('Same storage terms and attribution as geocode') is about licensing, not tool selection.

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