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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds useful scope context (what the corpus covers) but says nothing about pagination, ordering, or result sizing. With annotations carrying the behavioral burden, this is an adequate but not rich disclosure.

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?

Purpose is front-loaded in the first clause, followed by coverage enumeration and the usage rule. The long topic list is informative for discovery but slightly padded; still two sentences with no wasted framing.

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?

An output schema exists (so return shape needn't be described) and annotations cover the safety profile. Purpose, coverage scope, and the alternative tool are all present — nothing an agent needs to call this correctly is missing.

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?

Only one parameter (locale) and the schema documents it at 100% coverage with an enum. The description adds no locale guidance, so the baseline 3 applies — the schema does all the work here.

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 the Harness Engineering Handbook chapters'), gives the ID prefix (HRN-001…) and enumerates the corpus scope, so an agent knows exactly what this returns. It is clearly distinguished from sibling get_handbook and from search.

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 routes the agent: 'Use this to see the chapter map; use `search` when you have a topic rather than a chapter.' Both the when and the when-not (with a named alternative) are stated.

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