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

Annotations already declare read-only, idempotent, non-destructive, so the safety profile is covered. The description adds real value beyond the schema by explaining status values (estimated | announced | confirmed | moved, with original dates preserved) and how to interpret data_confidence ('high' = all announced/confirmed, 'medium' = something estimated). It does not cover caching or data freshness limits beyond 'last-checked time'.

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 what it returns and scoped by, then usage, then a concrete example. It is somewhat dense — the first sentence packs names, dates, status, source URL and last-checked time — but almost every clause carries information an agent would otherwise have to infer.

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?

An output schema exists, so enumerating return fields is optional, yet the description usefully highlights confidence semantics and the estimated_items/sources/data_version envelope. Minor gap: it says 'list all' without noting the include_estimated filter default, which slightly understates its own behavior.

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% with rich per-parameter descriptions and enums, so the schema carries the load. The description's example ({year:2026, emirate:'federal', sector:'private'}) adds a little illustration but no new semantics, and include_estimated is never mentioned in the 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?

States a specific verb (list) and resource (public holidays) plus the exact scoping axes: Gregorian year, emirate, sector. It is clearly distinguishable from siblings like next_holiday and working_days_between, which answer point/deadline questions rather than enumerating a year.

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 cases (annual planning, HR calendars, showing provisional dates) that tell the agent when this is the right tool. It stops short of naming alternatives or exclusions — e.g. 'for the next upcoming holiday use next_holiday' is absent, and nothing says when not to use it.

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