geom_great_circle_distance

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

No annotations are provided, so the description must fully disclose behavioral traits. It states the tool calculates distance, implying a read-only, non-destructive operation, but does not elaborate on output format (e.g., units), error handling, or computational characteristics (e.g., precision, limitations). For a tool with no annotations, this is insufficient to guide the agent effectively.

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 extremely concise and front-loaded, consisting of a single sentence that directly states the tool's purpose. There is no wasted verbiage, and the domain/category tags are efficiently appended. This is a model of brevity and clarity in structure.

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 tool's complexity (4 required parameters, no output schema, no annotations), the description is incomplete. It lacks details on parameter semantics, behavioral traits, and output expectations. While conciseness is high, the description does not provide enough context for the agent to use the tool confidently without additional inference or trial.

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?

The input schema has 0% description coverage, so the description must compensate. It mentions 'GPS coordinates' and 'two points', which hints at the parameters (lat1, lon1, lat2, lon2), but does not explain their semantics (e.g., units, valid ranges, coordinate systems). This leaves critical parameter details undocumented, failing to adequately supplement the bare schema.

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 tool's purpose: 'Calculate great circle distance between two points on Earth (GPS coordinates)'. It specifies the verb ('calculate'), resource ('great circle distance'), and domain context ('GPS coordinates'). However, it does not explicitly differentiate from sibling tools like 'distance_haversine' or 'geom_distance', which may serve similar purposes, so it falls short of a perfect score.

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 minimal usage guidance. It mentions the domain ('geometry') and category ('general'), but does not specify when to use this tool versus alternatives (e.g., 'distance_haversine' or 'geom_distance'), nor does it outline prerequisites or exclusions. This leaves the agent without clear direction on tool selection.

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