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

The readOnlyHint already covers the safety profile, and the description adds extra context: the built-in sandbox scope and the non-obvious detail that returned entries include run duration. It does not contradict the annotation, and the missing details (e.g., exact time units) are minor for a parameterless read-only list.

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?

It is a single sentence with the action verb and resource up front, followed by the sandbox scope and the duration detail. Every clause carries useful information and there is no filler.

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 zero-parameter, annotation-covered read-only list tool, this description is functionally complete: it names the resource, the environment scope, and the key returned field (duration). More detail about exact result shape or time units would be useful but is not necessary for deciding to call it.

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 input schema has no properties, so there are no parameter semantics to explain; the 0-parameter baseline applies. The description usefully focuses on what results will contain rather than inputs.

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 uses a specific verb ('List'), a specific resource ('OCPI charging journeys'), and a clear scope ('built-in sandbox'), while adding the result detail that the tool also reports each journey's duration. This distinguishes it from siblings like list_conformance_suites and list_ocpi_versions, which target different resource types.

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?

The description clearly communicates the relevant use case: discovering which OCPI charging journeys are runnable against the built-in sandbox and how long they take. It does not explicitly name alternatives or state when not to use it, so it doesn't reach the top score.

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