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

Annotations already disclose readOnly, idempotent, and non-destructive behavior, so the description only adds return-content context (full Markdown body, provenance, related ids). No additional behavioral context such as auth needs, error behavior, or rate limits is provided.

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?

Two compact sentences with the core action first, a concrete id example, return summary, and a usage pointer. Every sentence earns its place with 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 simple get-by-id tool with full parameter schema, an output schema, and annotations covering safety/idempotency, the description is complete. It also supplies the required prerequisite workflow (search/list_handbook first), which is the key contextual information an agent needs.

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 schema already explains id as 'HRN-001' or slug and locale with an enum/default. The description repeats the id example but adds no parameter meaning beyond the schema, so it warrants the baseline 3.

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 ('Get'), resource ('Harness Engineering Handbook chapter'), and key selectors (id/slug), and gives a concrete id example. It is clearly distinct from sibling list_* and get_* tools targeting other resources.

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?

Explicitly tells the agent to call this only after search or list_handbook has produced an id, which is clear when-to-use guidance. It does not spell out when-not-to-use or name alternatives like other get_* tools, so it stops short of a 5.

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