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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive, covering the safety profile. The description adds meaningful behavioral context beyond annotations: the response includes both UTC and formatted local time, and there is a strict user-facing disclosure obligation about the calculation authority method via authorityNotice.

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?

Two sentences with zero wasted words the retrieval action and scope are front-loaded, followed by the high-priority disclosure directive. Every sentence earns its place.

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?

An output schema exists, so return value documentation is not the description's job. The description covers the prayer times returned, the dual time formats, and the mandatory disclosure, while all seven optional parameters are fully captured in the schema. It could have explicitly mentioned the auto-resolution default, but that is already present in the calculationMethod parameter description.

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 description coverage is 100%, with each parameter already documented and enums provided for madhab and calculationMethod, so the baseline of 3 applies. The description does not add semantic detail about parameters; the authorityNotice reference is about the response behavior rather than input meaning.

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 ('Retrieves') and a clear resource ('today prayer timetable') and enumerates the exact set of returned times (Fajr, Sunrise, Dhuhr, Asr, Maghrib, Isha). The full-day scope distinguishes it from the sibling get_next_prayer without needing to open either 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?

Provides no guidance on when to use this tool versus siblings such as get_next_prayer, get_prayer_status, or configure_prayer_preferences. The MANDATORY disclosure requirement is an invocation condition, not a selection guideline, so there is no when-to-use or when-not-to-use information.

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