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

The annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and a closed-world scope, so the safety profile is fully covered. The description adds value by enumerating the returned attributes, but says nothing about ordering, completeness, or whether the list is stable — though for a parameterless reference list those gaps are minor.

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 what is returned and closed with the decision it supports — no filler. The awkward clause about which truck types Lane Cost prices slightly muddies the opening but does not waste space.

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 parameterless, read-only enumeration with no output schema, the description supplies the essential missing piece — the shape of each record. An agent has enough to decide whether to call it and what to expect. Only the relationship to the rate siblings remains unstated.

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 tool takes zero parameters, which is the baseline-4 case; there is nothing for the description to disambiguate. The schema's additionalProperties=false correctly signals a no-argument call, and the description is consistent with that.

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 the resource (truck types) and what accompanies each entry — deck size, capacity, pallet count, typical freight — so an agent knows this is a static reference list rather than a rate lookup like its siblings. The phrasing 'The truck types Lane Cost prices' is grammatically awkward and never uses an explicit verb like 'list', which keeps it from a 5, but the intent is still unambiguous.

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?

'Use it to pick the right truck for a load' gives a concrete decision context, so usage is implied rather than absent. It does not name an alternative or state when not to call it, and it never explains the relationship to the rate-oriented siblings such as estimate_lane_rate or get_lane_rate_history.

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