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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuinely new behavior: footnotes are returned, and long chapters are paged by paragraph rather than truncated — useful for an agent deciding whether one call suffices.

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 short sentences, zero filler, with the core capability front-loaded and pagination caveat second. Nothing to cut.

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 tool with full annotation coverage and no output schema, the description covers the essentials: content, footnotes, and pagination. Minor gaps remain around whether pagination metadata (total paragraphs) is returned and what happens on an unknown slug.

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 description coverage is 0%, so the description carries the burden; it does clarify that 'slug' identifies the chapter and that paging is by paragraph, hinting at what limit/offset mean. However, it never states that limit counts paragraphs, nor mentions the default of 40 or the max of 80, leaving the agent to guess units and sensible values.

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 ('Text of one chapter by slug') plus the notable inclusion of footnotes, which is more precise than the title 'Get chapter'. It implicitly contrasts with list_chapters by scoping to 'one chapter', but never names the sibling, so differentiation requires a small inference.

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?

Usage is only implied: an agent can infer this is the tool for fetching chapter content versus listing chapters. There is no explicit statement of when to prefer it over search_book or list_chapters, and no prerequisites (e.g., slug must come from list_chapters or a work's chapter listing).

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