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

Annotations already declare read-only, idempotent, closed-world, so safety is covered. The description adds genuinely new behavior: it returns 'not_announced' rather than guessing when no rule is published, and it explains data_confidence semantics and the presence of estimated_items/sources. It repeats some return-shape info that the output schema already carries, keeping it from a 5.

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-loaded with purpose, then fallback behavior, then usage, then an example — a sensible order with no filler sentences. It is dense and long-ish, and the return-field enumeration is partly redundant with the output schema.

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?

Given three parameters with two enums, full schema coverage, and an existing output schema, the description covers everything an agent needs: purpose, fallback semantics, confidence model, and an example call.

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 baseline is 3. The description goes beyond the schema by giving a worked example ({year:2026, emirate:'federal', sector:'public'}) that ties parameter combinations to expected output, and by framing dates as 'observed or estimated'.

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+resource: returns Ramadan start/end for a Gregorian year AND the officially published reduced working-hour rules per emirate/sector. This clearly separates it from siblings like working_hours (general hours) and list_holidays (holiday enumeration).

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?

"Use for scheduling during Ramadan and for HR policy questions" gives clear usage context. It does not explicitly name alternatives or exclusions (e.g. 'use working_hours for non-Ramadan queries'), so it stops short of full routing guidance.

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