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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description goes well beyond that by disclosing the exact return structure (interlinear table, flowing English, editors' note, citation, reader links) and the hard cardinality cap of two passages per call. No contradiction with the read-only, non-open-world annotations.

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 and payload are front-loaded in the first clause, and the ref-format examples are genuinely useful rather than filler. The middle runs a bit long as a single dense sentence, but nearly every clause carries routing or format 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?

With no output schema, the description must describe returns itself, and it does so comprehensively (interlinear fields, translation, note, citation, links). The cardinality limit and ref syntax examples close the remaining gaps an agent would need before calling it.

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 adds real value by disambiguating what 'ref' means per book ('1.1' as Odyssey book/line vs. Platonic Stephanus page vs. John 1:1 vs. Thomas saying 77), which the schema does not. The neighbor enum and book lookup hint are already in the schema, so this is additive rather than exhaustive.

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 ('Returns ONE passage of a book as an interlinear') and enumerates exactly what the payload contains, from the word-by-word table to the reader links. This clearly distinguishes it from siblings list_books, lookup_word, and search, which return lists, single words, or query results rather than a full annotated passage.

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 clear context for use (fetching/quoteready passage content, citing via the citation string and reader link) and an explicit exclusion ('never more than two passages per call; whole chapters or books are not available, by design'), which steers large-scope needs elsewhere. It stops short of naming an alternative tool for those broader needs, so the routing guidance is implied rather than explicit.

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