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

Annotations already declare read-only, idempotent, non-destructive and closed-world. The description adds two pieces of context the annotations don't carry: that 'one call counts as one geocoding request' (quota/cost) and that the result matches geocode_search's fields (return shape, useful with no output schema). Neither rate limits nor error behavior are covered.

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 sentences, front-loaded with the core operation, then the detail semantics, then cost and return-shape notes. The middle enumeration is long but each level earns its place; the only friction is the slightly awkward 'same fields as those of geocode_search' phrasing.

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_search for the result shape, and it discloses quota cost. All four parameters are accounted for between schema and description. A note on what happens when no address exists at the point (empty result vs. nearest fallback) is the main missing piece.

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 the baseline is 3, but the description adds meaning beyond the schema: it documents the default for detail ('address, the default') which the schema does not, and explains that street/district/city/county/state/country are the containing units of the point. It says nothing about the language parameter, which is left to the schema.

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 type (reverse geocoding), which cleanly separates it from geocode_search, which goes the other direction. It references geocode_search only for output fields, so the differentiation is implicit rather than spelled out.

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 reverse-geocoding framing makes the use case (you have coordinates, you want a place name) clear, and the detail parameter is described as a choice among levels. No explicit when-not-use or named alternative (geocode_search for forward lookups) is given, so the exclusion side is missing.

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