Convert a city or town name into geographic coordinates for Facebook Marketplace listing searches, enabling accurate location-based filtering of results.
Look up a city/town name to get coordinates for use with search_listings
| Name | Required | Description | Default |
|---|---|---|---|
| query | Yes | Location search query (e.g. 'Dedham MA', 'Boston', 'Brooklyn NY') |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations provided, so description carries full burden. It accurately describes the read-only lookup behavior and implies output of coordinates. No contradictions or missing critical traits.
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 waste. It front-loads the action and purpose efficiently.
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 simple single-parameter tool with no output schema, the description covers the essential use case. It could mention coordinate format, but completeness is adequate given the tool's simplicity.
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% with a well-described query parameter. The description 'for use with search_listings' adds slight context beyond the schema, but does not significantly enhance parameter understanding.
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 verb 'Look up', the resource 'city/town name', and the outcome 'get coordinates for use with search_listings'. It distinguishes from sibling tools like search_listings by specifying it's a geocoding step.
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 explicitly ties the tool's use to preparing coordinates for search_listings, providing clear context. It doesn't list alternatives or when not to use, but the purpose is sufficiently narrow.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.