Upcoming holidays

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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so safety is covered. The description adds genuine behavior beyond that: the window begins today by default, each result carries a days-until value, and weekly Fridays are deliberately excluded from the list.

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 compact sentences plus a short exclusion clause; the scope statement is front-loaded and the usage hint and caveat follow in priority order. No filler and nothing repetitive.

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?

For a simple three-parameter read tool with full schema coverage and no output schema, the description covers origin of the window, result contents and a notable exclusion. The only missing piece is disambiguation from related holiday tools in the same family.

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 count, calendar and from_date are already documented, including the YYYY-MM-DD format and the 'omit for today' default. The description only reinforces from_date's default behavior and adds nothing about how the calendar choice affects the returned days-until values or formatting. Baseline 3 applies when the schema carries the load.

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 uses a specific verb and resource ("List the next official holidays in Iran") and defines the starting point (today or from_date) plus a return attribute ("days until each"). It is clearly a forward-looking listing rather than a calendar lookup, but it never references the sibling ti_holidays or ti_long_weekends, so an agent must infer the boundary between them.

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 supplies a concrete trigger phrase ("Use for 'when is the next holiday'") and a scope exclusion ("Fridays alone are not listed"), which prevents a common misread. It does not, however, state when to prefer ti_holidays or ti_long_weekends instead, so the alternative-tool routing is left implicit.

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