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

The annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful behavior beyond that: the payload is compact and omits linked verse text, which tells the agent to expect a lightweight result. It does not describe ordering or result limits, but the output schema carries the return shape.

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?

Two sentences, zero filler, with the core behavior front-loaded and the sibling routing placed after it. Every clause carries selection-relevant 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 one required parameter, an output schema, and full annotations, the description covers what the agent needs to select and call it. The one residual gap is that it does not say whether ranges or whole chapters (allowed by the schema) behave differently from a single verse.

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% and the single reference parameter is fully documented in the schema, including accepted formats and abbreviations, so the baseline is 3. The description adds nothing beyond that and actually says 'one verse' while the schema permits ranges and chapters, leaving ambiguity about whether those inputs are supported here.

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?

The description names a specific resource and shape: a compact list of Bible references cross-linked to one verse, explicitly without their text. It also implicitly distinguishes itself from related_passages, so an agent can tell the two apart without opening either 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?

It gives an explicit when-to-use condition ('when you only need references to follow up') and names the alternative (related_passages) along with the tradeoff that it returns more detail. Nothing about tool selection is left to inference.

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