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

Annotations only cover readOnly and closed-world, but the description adds cost ($0.01), the stale snapshot date, straight-line-only accuracy, absence of potable-water assurance and road routing, and licensing terms. These are exactly the caveats an agent needs before charging a call.

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?

Four tight sentences, front-loaded with purpose then cost, then caveats, then licensing. Each sentence carries distinct information with no restatement of the name or schema.

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?

For a 5-parameter, zero-coverage tool with no output schema, important gaps remain: what a returned station record contains, result ordering, and how service 'either' behaves are all unstated. Cost and staleness are well covered, but the call-shaping and result-shaping details are not.

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 description coverage is 0% across 5 parameters, and the description never mentions latitude, longitude, limit, radius_km or the service enum values. The phrase 'bounded straight-line proximity' does meaningfully imply that radius_km is a crow-flies radius rather than driving distance, which is the only semantic gain.

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 ('Nearest RV dump/water stations') plus the exact data source and snapshot date. Nothing in the sibling list (check_*, preflight_*, lint_*, size_solar) overlaps, so an agent can select this unambiguously.

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?

Explicitly carves out what this is not ('not live access, potable-water assurance or road routing') and points to the free underlying projection under ODbL as an alternative. It stops short of naming a sibling tool or stating a positive 'use this when' condition, which keeps it below a 5.

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