Get full car status

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

Annotations already declare readOnlyHint and openWorldHint, and the description adds useful behavioral context: it discloses 'Costs several domain reads (cached)' and notes 'data age for each,' giving agents insight into performance and data freshness without contradicting the annotations.

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?

The description is two sentences: the first front-loads the purpose and enumerates the contents, the second gives cost and the alternative. There is no wasted wording, and the key information is presented early.

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?

Given the presence of an output schema (which explains return values) and annotations (readOnlyHint, openWorldHint), the description adequately covers the tool's aggregate nature, cost, and usage. It doesn't describe the output structure, but that is handled by the schema. The minor gap is missing explicit when-not-to-use guidance, but that's a usage-guideline issue more than a completeness issue.

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 single parameter (vin) is fully described in the schema with 100% coverage, including optionality and default behavior when omitted. The description adds no additional parameter information, so the baseline of 3 is appropriate since the schema handles the semantics.

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 clearly states the tool's purpose: 'One-call status of the car' and enumerates the specific data fields (charge level, range, lock/doors, etc.). It distinguishes itself from sibling get_* tools by explicitly saying 'use instead of calling five get_* tools,' making the unique role obvious.

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 gives a clear use case ('use instead of calling five get_* tools') and implies when to use this aggregated tool versus the individual getters. However, it doesn't explicitly state when NOT to use it (e.g., if only one field is needed), though that is strongly implied by the alternative wording.

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