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

With no annotations, the description carries the full burden and does disclose the two non-obvious traits: determinism (same date -> same verse) and uniform sampling over the corpus, which tell an agent the result is stable and not curated/weighted. It stops short of describing the return payload (e.g., verse text vs. reference) or corpus size.

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 front-loaded sentence with no filler; the determinism guarantee, the primary behavioral fact, appears first.

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?

For a one-optional-parameter read tool, the essential unknown (is the output reproducible?) is answered and the date parameter is fully covered by schema. The notable remaining gap is that no output schema exists and the description does not say what a 'verse' includes (text, reference, translation).

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 schema already documents the YYYY-MM-DD format and the UTC 'today' default, so the description adds no syntax detail. At most 'same calendar date' reinforces the date-keying semantics, which is baseline-level contribution.

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?

Names a specific resource ('verse of the day') and a precise behavioral property (deterministic, date-seeded). That is enough to tell it apart from get_verse, search_verses, and the other siblings in practice, though it never explicitly contrasts itself with them.

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: an agent infers it is for 'give me the verse for today/this date' rather than lookup or search. There is no explicit when-to-use, when-not-to-use, or named alternative such as 'for arbitrary filtering use search_verses'.

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