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

Beyond the annotations, the description discloses the algorithmic behavior ('move one day at a time; decrement only on status.is_working_day=true'), the weekend baseline (Friday-Saturday), exclusions (remote-work/operating-hour decisions), data freshness constraints for Islamic dates, and the exact REST fallback endpoint. This is rich behavioral context that annotations alone do not provide.

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 structured with clear sections and front-loads usage guidance, but it is long and includes an unnecessary enumeration of all output fields despite the presence of an output schema. Several lines repeat schema information, reducing conciseness without adding proportional value.

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 a 2-parameter tool with annotations and a full output schema, the description is thorough: it covers scope, exclusions, computation logic, examples, fallback access, and documentation links. An agent has everything needed to select and invoke it correctly.

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 both parameters are already documented in the input schema. The description lists the same inputs and repeats a JSON example already present in the schema, adding only minor clarification ('signed offset; start date excluded for non-zero offsets') that is already captured by the schema description.

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: adding or subtracting Egypt authority-scope working days. It distinguishes this from siblings by naming the Egyptian government/public-sector holiday scope and the Egypt-specific calculation, so an agent can separate it from check_eg_working_day or count_eg_working_days.

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?

It gives clear when-to-use guidance ('when you need a deterministic Egypt working-day offset') and calls out when not to use it (private employers, banks, schools, diplomatic missions, sector calendars). It does not explicitly name the alternative sibling for single-date checks or counts, so it falls short of a full 5.

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