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

Annotations already declare read-only, idempotent, non-destructive, closed-world behavior. The description adds valuable output context absent from an output schema: one card per manual year and the specific fields returned. It still does not mention pagination, limits, or whether every year is always included.

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?

A single dense sentence front-loads the resource and then lists the returned fields. There is no redundant phrasing or filler, and the structure is easy to scan.

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 one-parameter, read-only lookup with full schema coverage and no output schema, the description supplies enough output detail to call the tool confidently. The main missing piece is whether all manual years are returned or only a subset, but that is a minor gap for this tool class.

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%, so the platform parameter is already fully documented, including its dependency on list_platforms. The description reinforces that it applies to one engine platform but adds no format or validation detail beyond the schema.

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 names a specific resource (owner's-manual service cards for one engine platform) and enumerates the exact contents returned: oil capacity, oil grade/spec, filter numbers, and coolant. This clearly distinguishes it from sibling tools like get_repair_cost, get_failure_modes, and find_part_number without requiring the schema to be opened.

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 does not state when to use this tool instead of related siblings or whether all manual years are returned at once. The only usage hint is in the schema (platform id from list_platforms), not in the description itself.

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