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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: a single label may map to multiple ids and all of them must be passed, which affects how the caller uses the result. It omits return shape and pagination, keeping it short of a 5.

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?

Three short sentences, front-loaded with the purpose before the rationale. Each sentence carries information, though the middle sentence is slightly conversational rather than directive.

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?

No output schema exists, and the description partly compensates by indicating that card_ids are the payoff, but it does not describe the returned structure or whether results are paginated. For a simple single-parameter list tool this is nearly sufficient.

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% and the query parameter is already documented with an example ('chargemap') and default behavior. The description adds nothing about the query parameter itself; the 'pass all of them' note concerns downstream ids rather than this input. Baseline 3 applies.

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 ('List charging cards and subscriptions') plus the outcome it enables ('to get the card_ids of the ones the driver has'). Siblings find_vehicle and search_chargers cover clearly different resources, so an agent can route without ambiguity.

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?

Gives a clear motivating context: use this to obtain card_ids, and explains that an owned card/plan can beat a charger's walk-up price. It does not name an explicit alternative or a when-not condition, but the trigger condition is unambiguous.

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