facebook_marketplace_city_coordinates

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

With no annotations provided, the description bears full responsibility for behavioral disclosure. It fails to mention crucial traits such as read-only nature, rate limits, response format (e.g., lat/lng array), behavior when city is not found, or how multiple results are returned. The 'exactly_one' parameter hints at multiplicity but the description does not explain the default behavior.

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 of 10 words that conveys the core purpose without any fluff. It is front-loaded with the action and resource. Every word earns its place, achieving maximum conciseness.

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 geocoding tool, the description covers the basic intent but lacks details about output format, error handling, or typical result count. Given no output schema and no annotations, the description should provide more context. However, the tool is low complexity, so it meets a minimal standard but is not fully complete.

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 descriptions for all three parameters. However, the description adds no extra meaning beyond the minimal schema text. For example, 'Country name or code' could be clarified as ISO code or full name, and 'exactly_one' does not specify what happens when false or missing. Since schema already defines basics, a baseline of 3 is appropriate.

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 'Get' and the resource 'GPS coordinates for a city', and specifies the purpose 'to use as Marketplace location filters'. This distinguishes it from sibling tools like facebook_marketplace_search or facebook_marketplace_categories, which have different functions.

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 does not provide any guidance on when to use this tool versus alternatives. It lacks context about prerequisites, limitations, or comparisons to other location-related tools like facebook_search_locations. The agent receives no direction on typical usage scenarios.

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