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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety bar is covered. The description adds real behavioral context beyond that: the country default, what the result carries (calculation dates, scenario, fare, location scope), and a no-fabrication guarantee that unavailable routes are not substituted with nearby towns.

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?

Dense and front-loaded, with the scope sentence first and the default and guarantees after. The clause 'Read calculation dates, scenario, fare and location scope' is slightly awkward and partly redundant with the output schema, costing a point.

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?

With annotations covering safety and an output schema covering returns, the description supplies the domain framing, default value, and failure semantics an agent needs. Only edge behavior for unsupported communes is left 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?

Schema coverage is 0%, so the description must carry the load, and it does: it explains that commune is a municipality centre in a supported country, that country defaults to LU, that destination is one of six Luxembourg employment hubs, and that mode spans four options. It stops short of clarifying the expected commune naming format or what each destination slug denotes.

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 resource (municipality-centre commute scenarios) with concrete scope: origins in LU/FR/BE/DE, six Luxembourg employment hubs, four modes. No sibling tool covers commute computation, and the description makes that unique role unmistakable.

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?

Usage is implied by the scenario framing and the 'Country defaults to LU' default, but there is no explicit when-to-use/when-not guidance or named alternative. For a tool with no close sibling this is tolerable, but the agent must infer the trigger condition.

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