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

Annotations already establish readOnly, idempotent, and non-destructive behavior. The description adds useful context about the corpus and chapter scope, but does not disclose much additional behavioral detail beyond the basic listing behavior. This is acceptable given the strong annotation coverage.

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 front-loaded with the core action and resource, followed by useful corpus context and a clear usage instruction. The enumerated topic list is somewhat long but adds helpful context about what the handbook covers, so it earns its place.

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 simple, read-only listing tool with one optional parameter, a full output schema, and strong annotations, the description is complete. It states what the tool does, what it returns conceptually, and when to use a different tool.

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 schema fully describes the single optional `locale` parameter, including its enum values and default behavior, so the description does not need to add parameter details. The description's mention of chapters and search routing provides context but not parameter-level 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 opens with a specific verb and resource: 'List the Harness Engineering Handbook chapters'. It also clarifies the scope and nature of the tool by describing the corpus and what the result represents, distinguishing it clearly from related list/get/search siblings.

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 explicit guidance: use this tool to see the chapter map, and use `search` when the user has a topic rather than a known chapter. This directly helps an agent choose between list_handbook and search alternatives.

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