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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the lower bar applies. The description still adds genuine behavioral detail: data_confidence semantics, estimated_items, sources, data_version, and the flag that private-sector weekends are employer-set. Good value beyond annotations.

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 the core operation, then use cases, then an example, then return shape. Every sentence carries information, though the example and return-field enumeration make it longer than strictly necessary.

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 an output schema exists, the description needn't restate return values but does so usefully for the confidence/estimation semantics. Combined with a fully covered input schema, an agent has everything needed to call it correctly; the only omission is sibling routing against compute_deadline/working_days_between.

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 schema documents every parameter including the negative-days semantics. The description reinforces negative counting and supplies a worked example using start_date/days/emirate/sector, but adds little syntax or meaning beyond the schema. Baseline 3 is appropriate.

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 operation (compute a date N working days after/before a start date) with the key qualifiers (UAE emirate/sector, weekend and public-holiday skipping). An agent can distinguish it from siblings like is_working_day or list_holidays. It does not explicitly distinguish it from compute_deadline or working_days_between, which is the only clarity gap.

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?

Gives concrete use contexts (SLAs, delivery promises, HR processing times, 'within X business days' wording). No explicit exclusion or routing versus the closest siblings (compute_deadline, working_days_between), so it stops short of full when/when-not guidance.

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