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

Annotations already cover the read-only/idempotent/non-destructive profile, and the description adds substantial context on top: return contents (text, chapter, link, licence), the ~40,000-character pagination trigger, and the 3-questions-per-day limit with a 15-minute coalescing window for anonymous users. That rate-limit and auth disclosure is genuinely useful behavioral information not present in the structured fields.

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?

Three sentences, front-loaded with purpose before return behavior and access constraints, and no sentence is filler. It is dense but each clause carries information an agent needs (identifier source, pagination, quota).

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?

With no output schema, the description steps in to describe the return payload (text plus chapter, link and licence) and the pagination behavior of long chapters. Combined with the quota/auth constraints, an agent has everything needed to invoke this correctly and interpret the result.

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%, so the baseline is 3, but the description goes beyond the schema by explaining why `page` exists - chapters longer than ~40,000 characters come in pages - which the schema's one-line description does not convey. It adds meaning without contradicting the schema's type/bounds.

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 (a chapter/section of The Sourdough Framework), and pins the identifier source to get_sourdough_book_contents, cleanly separating it from search_sourdough_book. An agent can tell what this does and where the `part` value comes from without opening the schema.

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 to get_sourdough_book_contents for chapter numbers and clarifies that the table of contents, guides and calculators need no account, which sets expectations about prerequisites. It never names search_sourdough_book as the alternative for lookup-by-topic, so the when-not-to-use side is only implied rather than stated.

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