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

Annotations already indicate a safe, idempotent read operation, and the description adds important behavioral limitations beyond them: the result is computed, may be ±1 day versus the moon-sighted UAE date, and always reports data_confidence, estimated_items, sources, and data_version. It also explains the semantics of 'high' versus 'medium' confidence.

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 front-loaded with the conversion direction, range, and method, then immediately adds the key caveat and response metadata. Every sentence contributes useful information without unnecessary padding.

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 an output schema already present, the description does not need to enumerate return fields, but it still highlights the most important response metadata and the ±1 day accuracy caveat. Combined with the annotations, it provides everything an agent needs to call the tool correctly and interpret its output.

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%, so the only parameter is already well documented. The description repeats the format and range and adds a useful example, but does not provide meaningfully deeper semantics beyond what the schema already states.

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 and resource ('Convert a Hijri date ... to Gregorian'), including the supported range and method. It clearly distinguishes this tool from its inverse sibling gregorian_to_hijri by naming the conversion direction explicitly.

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 gives clear context for when to use this tool by naming the input calendar and date range. It does not explicitly mention alternatives such as gregorian_to_hijri, but the conversion direction makes the intended use unambiguous.

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