OpenStreetMap Tagging Schema MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes the tool's behavior by detailing the validation checks performed (deprecation, schema existence, option validation, field type checking) and the return format ('detailed validation results with localized names and actionable messages'). It does not mention potential limitations like rate limits or authentication needs, but covers core functionality well.

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 appropriately sized and front-loaded, starting with the core purpose and then listing validation aspects and usage contexts. Every sentence adds value, but it could be slightly more concise by integrating the usage guidelines more tightly with the purpose statement.

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 of validation tasks and no output schema, the description provides a good overview of what the tool does and returns. It covers validation aspects and usage contexts adequately, but could benefit from more detail on output structure or error handling to be fully complete for a tool with no annotations or output schema.

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 both parameters ('key' and 'value') with detailed descriptions. The description does not add significant meaning beyond what the schema provides, such as specific examples or edge cases not covered in the schema. Baseline 3 is appropriate as 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 specific action ('validate a single OpenStreetMap tag key-value pair against the OSM tagging schema') and distinguishes it from sibling tools like 'validate_tag_collection' by emphasizing it's for single tags. It lists comprehensive validation aspects (deprecation checking, schema existence, option validation, field type checking) that make the purpose explicit and 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 description provides clear context for when to use this tool ('for educational purposes, data quality checks, or validating individual tags before bulk operations'), which helps differentiate it from alternatives like 'validate_tag_collection' for bulk operations. However, it does not explicitly state when not to use it or name specific alternatives, keeping it from a perfect score.

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