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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds substantial non-obvious behavior: the three renderings returned (body/amiri/majma), the surah_ayat total-count field, that runs continue across surah boundaries with per-verse surah/aya, and that response_format 'none' is preferable when the caller parses structuredContent due to a shared character budget.

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?

Purpose is front-loaded, followed by resolution modes and then examples that each illustrate a distinct invocation pattern. It is longer than strictly necessary but nearly every sentence carries operational information; the examples in particular earn their space.

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 and five parameters, the description compensates by naming the returned fields (body, amiri, majma, surah_ayat) and explaining the two-channel response_format behavior. An agent has everything needed to call it correctly and interpret the result.

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 the baseline is 3, but the description adds cross-parameter constraints (mutual exclusivity of aya_id vs surah+aya) and semantic mapping of each field to a real call, e.g. count=4 returning all of al-Ikhlas. The worked examples meaningfully extend beyond the schema text.

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 ('Fetch Qur'anic verses') and immediately names the two resolution modes (cumulative aya_id 1..6236 OR surah+aya). An agent can distinguish this from shamela_search_quran or shamela_get_tafseer_of_aya without opening the schema.

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?

Explicitly tells the agent how to invoke it: 'Pass either aya_id alone OR both surah and aya', with four concrete worked examples covering basmala, mid-surah, full short surah, and a run. It does not explicitly name an alternative tool (e.g. search_quran) or state when not to use it, which keeps it just short of a 5.

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