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

Annotations already declare readOnly/non-destructive/closed-world, so the bar is lower; the description nonetheless adds the non-obvious pagination contract (long chapters arrive in parts, nextCursor → cursor). It does not explain roughly what 'everything under it' includes or how revisions relate to current content.

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 tight sentences, front-loaded with what is returned and followed by addressing modes and pagination. The em-dash nesting is dense but every clause carries information.

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?

All params are optional, annotations cover safety, and there is no output schema, so the description is mostly sufficient. The significant remaining gap is the relationship to the 'fetch' sibling — an agent cannot tell from this text which one to call for a chapter versus a single item.

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 only 50% — id and cursor have no schema descriptions — and the description compensates by explaining id provenance (index or search) and the cursor round-trip. Path and revision are covered by the schema itself, so the combined set is well explained.

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 ('read') and resource ('one chapter or section of the guide, whole, with everything under it'), and clarifies the two addressing modes (id or path). It implicitly links id to the index/search siblings but never distinguishes itself from the 'fetch' sibling, leaving a real selection ambiguity.

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?

Gives concrete usage context: obtain the id 'from index or search', or use the path, and tells the agent to feed nextCursor back as cursor for long content. It stops short of any when-not guidance, particularly versus 'fetch'.

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