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

Annotations already declare read-only, idempotent, non-destructive and closed-world behavior, so the safety profile is covered. The description adds genuinely useful context the annotations cannot convey: the midnight US Eastern rollover, the fixed one-verse-per-day list, word-for-word fidelity, licensing, and the data_updated_at field. It does not discuss failure modes for out-of-range dates.

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 what the tool returns and how the day boundary works, then covers parameters. The licensing sentence is boilerplate but short and legally relevant; nothing is badly padded.

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 no output schema, the description usefully names the returned text and the data_updated_at field, and explains the day-boundary semantics that an agent must know to pass a valid date. Adequate for a simple two-parameter read tool.

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%, so both parameters are already fully documented with patterns, enums and defaults. The description restates the translation options and the date window rather than adding new syntax or edge-case detail, 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?

Names a specific verb and resource ('Get the Bible verse of the day'), the upstream source (Lamplight), and the two available translations. The phrase 'fixed list of daily verses, one per calendar day' implicitly but clearly separates it from lookup_verse-style arbitrary lookups and from todays_reflection.

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?

Explains that the date parameter should cover yesterday, today or tomorrow so a reader in any time zone gets their own day, which is real usage guidance. It does not explicitly name when to prefer lookup_verse or todays_reflection instead, so it stops short of full alternative routing.

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