OpenStreetMap MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions 'Nominatim geocoding service,' which implies external API usage, but doesn't disclose critical traits like rate limits, authentication needs, error handling, or response format. For a search tool with external dependencies, this is a significant gap in transparency.

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 description is a single, efficient sentence that front-loads the core purpose without unnecessary details. It's appropriately sized for a search tool, with zero waste or redundancy.

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 the complexity (5 parameters, external API dependency) and lack of annotations and output schema, the description is incomplete. It doesn't address behavioral aspects like rate limits or response structure, nor does it guide usage relative to siblings. For a tool with these characteristics, more context is needed.

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 the schema already documents all parameters thoroughly. The description adds no additional parameter semantics beyond what's in the schema (e.g., it doesn't explain query formatting best practices or viewbox coordinate systems). Baseline 3 is appropriate when the schema does the heavy lifting.

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 states the tool's purpose: 'Search for locations, addresses, or places using Nominatim geocoding service.' It specifies the verb (search) and resource (locations/addresses/places) with the specific service (Nominatim). However, it doesn't explicitly differentiate from sibling tools like 'reverse_geocode' or 'search_by_tags,' which is why it doesn't achieve a perfect score.

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 provides no guidance on when to use this tool versus alternatives. It mentions 'Nominatim geocoding service' but doesn't explain when to choose this over sibling tools like 'reverse_geocode' (for coordinates to addresses) or 'search_by_tags' (for OSM tag-based searches). There's no mention of prerequisites, exclusions, or comparative contexts.

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