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

With no annotations, the description carries the full behavioral transparency burden. It discloses that the calculation is great-circle and offline, but does not mention output units, coordinate order, input format, or error behavior. This is a significant gap for a computational tool.

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 clear sentence with no filler, and the key concept is front-loaded. However, it is perhaps too sparse, omitting parameter syntax that would materially improve the definition.

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?

Although an output schema exists, the tool cannot be invoked correctly without knowing how to express two coordinate pairs in the single q parameter. The description does not provide enough input-construction detail, making the overall definition incomplete for an 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?

The schema has 0% description coverage for the q parameter, so the description must compensate. It tells the agent that two coordinate pairs are involved, but does not specify how they should be encoded in q, such as order, delimiter, or coordinate format.

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 identifies the tool as computing great-circle distance between two coordinate pairs, distinguishing it from geocoding, geohashing, and bearing tools. It lacks an explicit action verb, but the resource and computation are specific enough for an agent to understand the core purpose.

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 word 'offline' implies this is a local computation that does not require network access, offering some usage context. However, there is no explicit guidance about when to use this tool versus related geospatial tools like bearing, geohash, or pluscode, nor any exclusions.

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