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

Annotations already declare readOnly, idempotent, closed-world, non-destructive behavior, so the safety profile is covered; the description adds real context beyond that: a 50-verse cap, that copyright/license/source attribution is returned, and that output is unmodified source text. It does not discuss error behavior for out-of-range chapters or verses, so not a 5.

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 short sentences, each earning its place: capability and cap first, identifier format second, the negative guarantee last. No filler and the scoping constraint is front-loaded.

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?

An output schema exists, so return values need not be explained, and the description still adds the attribution content and the 50-verse ceiling. Coverage is strong for a read tool, with only minor gaps such as no guidance on the sibling search tool for locating passages by reference.

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 100%, with book_id, chapter, start_verse, and end_verse all documented including bounds and the inclusive-omit convention, so the baseline is 3. The description's mention of USFM IDs (GEN, PSA, MAT, JHN) largely restates the schema's own book_id description and adds only marginal new meaning.

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 up to 50 unchanged UBG verses from one chapter'), names the scope, and explicitly disclaims translation or AI generation, which distinguishes it from AI-search siblings like search_msza_ai. An agent can identify the operation 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?

Usage is implied by 'unchanged UBG verses' and 'No translation or AI generation occurs', which hints this is the verbatim-text tool rather than a search tool, but there is no explicit when-to-use statement and no named alternative (e.g., find_sessions_by_bible_passage or search_msza_ai).

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