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

With no annotations, the description has the full burden of behavioral disclosure. It adds the OSM Nominatim backend but does not disclose rate limits, usage policy, coordinate format constraints, or what happens when the optional q parameter is empty. These are meaningful details for a web-service-backed lookup.

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 entire description is a single compact clause that front-loads the operation, input, output, and provider. Every word contributes; there is no fluff or redundant restatement of the tool name.

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?

For a one-parameter reverse geocoder with an output schema, the description provides the core input/output contract. It is less complete in context because it does not address the ambiguities around q's optionality or the duplicate-sounding revgeocode sibling, and OSM-specific constraints are absent.

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?

The schema only exposes q with an empty default and no description, so the phrase 'lat,lon' adds essential meaning to the parameter. However, it does not explain the exact delimiter, allowed coordinate range, or why q is optional, so it only partially compensates for the 0% schema coverage.

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 states a specific operation ('Reverse Geocode') and the transformation ('lat,lon -> address'), with the data source 'OSM Nominatim'. This distinguishes it from forward geocoding (geocode), though a near-identical sibling 'revgeocode' is not differentiated.

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 Geocode' wording implies the tool should be used when the agent has latitude/longitude and needs an address, and not for address-to-coordinate lookups. However, it never explicitly names alternatives or exclusion conditions, leaving the choice to inference.

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