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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered; the description goes further by disclosing the verbatim-quote policy, the deduplication behavior ('also_under'), the excerpt/part mechanism, and the disambiguation response. It does not describe pagination via `limit` or ordering of results, which are the remaining behavioral gaps.

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?

Front-loaded with the core distinction, then a compact sequence of mode sentences that each carry distinct information, plus a closing block on quote handling. It is dense and long, but nearly every clause earns its place; the quote_id/excerpt material could be tightened.

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?

There is no output schema, and the description compensates by describing the return shape: profiles with book counts, verbatim quotes with attribution, `quote_id`, `excerpt` parts, and `also_under`. Combined with full schema coverage and annotations, an agent has everything needed to call it and interpret results.

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 genuine value by explaining the combinatorial semantics of `father`, `topic`, and `book` — which combinations trigger profile vs. scoped search vs. writer listing — something the per-property schema text does not convey. It says nothing about `limit` or `from_part`, which the schema covers only thinly.

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 ('Search the patristic corpus BY WRITER') and explicitly contrasts it with verse-based search, so an agent can route away from search_topic_verses or keyword_search immediately. The corpus size (62,484 passages from 314 writers) further pins down scope.

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?

Enumerates the parameter modes with concrete question examples for each: father alone for a profile, father+topic to search within a writer, topic alone across all writers, father+book for one book, nothing for the writer list. It also gives an explicit when-not/alternative rule for ambiguous names ('there are four Gregorys') and tells the agent to ask the user instead of guessing.

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