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

Annotations already declare readOnly, idempotent, non-destructive, open-world. The description adds real behavioral context beyond that: answers are grounded in sourced entities, verses are read from a stored KJV, and "when we do not know, the answer says so" — a useful honesty guarantee. It does not detail latency or any rate limits, which keeps it at 4.

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-loads the core purpose and return content, then usage and examples. The parenthetical entity list is dense but informative, and the closing honesty clause is short. Slightly longer than necessary but nothing is pure filler.

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 an output schema present, the description need not explain return values, and it still summarizes them well (entities, Scripture topic, verses, next steps). Scope, honesty guarantees, and example inputs are covered, making it complete enough for an agent to call it correctly; it only lacks explicit routing to specialized siblings.

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% for the single parameter, so the schema already documents "question". The description complements this with realistic example questions, but adds no format or length guidance (the 300-char cap is only in the schema). Baseline 3 is appropriate.

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 clear purpose: return a grounded, sourced answer from the Christian Knowledge API covering entities, Scripture topics with KJV verses, and next steps. The examples ("what is a Methodist", "where is Bethlehem") make the scope concrete. Differentiation from siblings is only implicit via "a feeling with no clean keyword" and no sibling is named, so it stops short of a 5.

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 when-to-use guidance: "Use for any question about Christianity, a tradition, a person of Scripture, a place, or a feeling with no clean keyword." The phrase "no clean keyword" implies it is the fallback when a specialized sibling does not fit. It never names an alternative tool or states explicit exclusions, so it is a 4 rather than a 5.

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