Calculate Heading

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

With no annotations, the description carries the full burden, and it leaves key traits undisclosed: the unit and range of the returned azimuth, whether it is true or magnetic north, and whether start/end order affects the result. It does imply a pure deterministic computation, but that is inference rather than disclosure.

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?

A single front-loaded sentence with zero filler; the verb, the computed quantity, and the input format all land in one clause.

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?

An output schema exists, so return-value explanation is not required, and the description names the input domain. The remaining gap is the convention behind the heading (units and reference direction), which an agent needs to interpret results correctly.

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 0% and neither 'start' nor 'end' is described in the schema, so the description must compensate. It partially does by stating the inputs are Maidenhead locators, which conveys the required string format, but it never says which endpoint is the origin or what a valid locator looks like.

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+resource ('Calculates heading') and disambiguates the term with '(azimuth)', which distinguishes it from the sibling calculate_distance without naming it. Sibling differentiation is implied by the resource noun rather than stated explicitly.

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?

No guidance on when to use this versus calculate_distance, no mention of prerequisites, and no exclusions. The only implicit signal is that inputs must be Maidenhead locators.

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