cityjson_extensions_registryFetch the official CityJSON Extensions registry and retrieve context around a search term to clarify extension definitions and usage.
Fetch the official CityJSON Extensions registry and optionally return context around a search term.
| Name | Required | Description | Default |
|---|---|---|---|
| query | No | ||
| max_chars | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must carry the behavioral disclosure burden. It states 'Fetch' (suggesting a read operation) but does not describe output format, truncation behavior, registry size, rate limits, or any side effects. The max_chars parameter hints at length control, but the description does not explain how the tool behaves around it.
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 sentence with no filler, and it front-loads the core purpose. It is efficient for a simple fetch tool, though the optional clause could be slightly more precise about what 'context' means.
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 tool with no output schema and no annotations, the description should explain what the response contains and how the parameters affect it. It does not mention the output type, what the returned context looks like, or how max_chars caps the result, leaving important details for the agent to discover.
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 0%, so the description needs to compensate for documenting parameters. It only partially covers 'query' by referring to 'a search term,' but max_chars is completely unexplained. The description adds minimal meaning beyond the schema's raw property names.
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 has a specific verb ('Fetch') and a clear resource ('official CityJSON Extensions registry'), and the optional search-term context clarifies a distinct feature. However, it does not explicitly contrast with sibling tools like cityjson_extension_schema, so differentiation relies on inference.
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 implies the tool is for browsing the registry and optionally searching within it, but it gives no explicit guidance about when to use this tool versus alternatives. There is no mention of when not to use it or how it relates to sibling registry/extension tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.