Check coverage

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), so the description's job is to add context — and it does, disclosing that a negative result carries a reason and that the outcome gates `analyse_plot`. It stops short of describing response shape, latency, or whether coverage boundaries are inclusive.

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?

Two short sentences, front-loaded with the core question and followed by the operational consequence. No filler. 'How finely the ground is measured' is a slightly roundabout way to say resolution but remains readable.

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?

There is no output schema, so the description must carry return-value meaning. It explains the `served` flag and that a reason accompanies a negative answer, but leaves the resolution value's name, units, and possible range unexplained — a gap an agent will hit immediately when reading the response.

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%: both `lat` and `lon` carry descriptions plus explicit min/max bounds in WGS84. The description adds nothing about the coordinate convention or bounding behaviour beyond the schema, so the baseline 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 states a specific function: determine whether RuralCheck can analyse a given point and at what ground resolution. It also distinguishes itself from the sibling `analyse_plot` by framing itself as the precondition that `analyse_plot` enforces, so an agent can separate the two without opening schemas. The phrasing 'Whether RuralCheck can analyse this point' is slightly indirect but unambiguous in effect.

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?

It gives a clear selection signal: `served: false` means `analyse_plot` will refuse the point, which strongly implies this is a pre-flight check to run before analysis. However, it never states the guideline outright ('call this before analyse_plot') and gives no explicit when-not condition, such as skipping it for already-known covered points.

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