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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is covered. The description adds only that the lookup is scoped to a single church father or writing passage; it discloses nothing about result shape, citation granularity, or behavior for an invalid id, which the output schema partially compensates for.

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?

A single sentence with no filler, and the essential input constraint (the id source) is placed where the reader hits it immediately. Nothing could be removed without losing 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 a rich annotation set, an output schema, and one fully documented parameter, the description covers what an agent needs to call it correctly. Only the lack of any note on citation format or empty results keeps it from a 5.

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?

There is one parameter with 100% schema description coverage, and the schema states the same provenance ('A writing passage id from search_writings or discussions_of'). The description restates rather than enriches that meaning, so the baseline 3 applies.

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 ('List the Bible verses that one ... writing passage cites') and bounds the scope to a single writing identified by passage_id. It is clearly distinguishable from siblings like search_scripture (find verses by text) or related_passages, since the resource here is 'verses cited by a given writing'.

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?

The description names the prerequisite input source explicitly ('by its id from search_writings or discussions_of'), which tells the agent this is a follow-up step after locating a writing passage. It stops short of naming an alternative tool or stating when NOT to use it, so it is strong context but not a full routing rule.

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