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

With no annotations provided, the description alone must disclose behavioral traits. It does convey the output structure (Arabic, transliteration, meaning, reflection, Quranic references) and adds a behavioral instruction ('Quote the Arabic exactly'), which is useful for downstream use. However, it does not mention failure modes, error handling, or what happens if both number and name are provided. For a simple read-only lookup, this is acceptable but not comprehensive enough to score higher.

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?

The description is a single, well-structured sentence that front-loads the core purpose and output fields, then adds a critical usage instruction. Every element earns its place, and there is no redundant information. The structure is ideal for an agent to parse quickly.

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 tool of this simplicity, the description covers the essential information: what it returns, how to select a Name, and a specific output instruction. It does not need to explain return values at a deeper level because the listed fields are self-explanatory. The only minor gap is handling of conflicting inputs (when both number and name are given), but this is an edge case not critical for typical use.

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?

The schema already provides 100% coverage of all three parameters (name, locale, number) with descriptions. The tool description adds minimal extra meaning: it clarifies the relationship between number and name (by number or by name) and hints at the output format. This is a marginal addition over the schema, so a baseline score of 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?

The description states a specific verb ('Returns') and a specific resource ('one of the 99 Names of Allah') with concrete fields (Arabic, transliteration, meaning, reflection, Quranic references). It clearly differentiates from siblings like find_verses and get_quran_verse, which target different content types. It also clarifies the two selection modes (number or name), leaving no ambiguity about what the tool does.

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 does not provide any guidance on when to use this tool versus its siblings (find_verses, get_dua, get_quran_verse). While the purpose implies it is for Names of Allah, there is no explicit mention of when to prefer it over alternatives, nor any exclusions or context about when it is appropriate. The only implicit signal is the resource type, which is not sufficient for robust tool selection.

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