lookup_by_coordinates

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

readOnlyHint=true already covers the safety profile, and the description adds real behavioral context: an external US Census Geocoder round-trip before the lookup, and equivalence of output to lookup_emission_factor. It omits failure behavior (non-US coordinates, geocode misses), which keeps it short of a 5.

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?

Three short sentences, front-loaded with what it does, then the mechanism, then the use case. No filler and every sentence carries distinct information.

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?

With no output schema, the description usefully states the return equals lookup_emission_factor's data, and explains the geocoding step. The main unaddressed gap is that the US Census Geocoder is US-only, so non-US coordinates fail silently as far as the description tells the agent.

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% and both parameters (lat, lon) are documented in the schema. The description restates 'latitude/longitude' without adding units, range, or formatting guidance, so baseline 3 applies.

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?

States a specific verb and resource ('look up emission factors') plus the input dimension ('by latitude/longitude'), and explicitly distinguishes itself from the sibling lookup_emission_factor by noting it returns the same data after geocoding. An agent can tell the two apart without opening a schema.

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?

Gives a clear selecting condition: 'Useful when you have a facility address or lat/lon but no ZIP,' which implicitly routes ZIP-holders to lookup_emission_factor. It never states that alternative as an explicit instruction, so the guidance is clear but not fully closed-loop.

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