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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered and the description needs only to add context. It adds none: it does not say whether the response contains verses, Arabic text, translation, or just surah metadata, nor how invalid IDs behave. The only extra content (range 1-114) duplicates the schema.

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?

One short sentence, front-loaded with the verb and resource, with zero padding. It is efficient but borders on under-specified rather than being deliberately tight.

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-parameter read tool with rich annotations this is close to sufficient, and no output schema exists so return values are not strictly required. However, the biggest open question for a surah lookup — whether verses are included or only metadata — is left unanswered, which affects how an agent plans follow-up calls.

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 'id' parameter is documented as 'Surah number (1-114)' with min/max constraints, so the schema does the work. The description merely restates the same range with no added meaning about ordering, indexing base, or edge behavior.

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 ('Get a single surah') with the keying parameter range, and the word 'single' implicitly contrasts with the sibling quran_list_surah. It stops short of naming that sibling, so the agent must infer the split from tool names rather than read it.

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 only implied: 'by its number' signals the agent must already know a surah ID, which nudges toward quran_list_surah when it doesn't. There is no explicit when-to-use statement, no stated prerequisite of discovering IDs first, and no named alternative.

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