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

With no annotations, the description carries the full disclosure burden. It does add two useful traits: 'PRO' signals a paid-tier/entitlement requirement, and 'typically current + next year' warns that coverage varies by dataset rather than being fixed. It says nothing about return size, ordering, pagination, or whether past years are included, which matters for a bulk-list endpoint.

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 short fragments with no filler, but the lead position is spent on the opaque 'PRO.' marker rather than the core behavior. It is terse to the point of under-specification rather than genuinely front-loaded.

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 one-parameter, no-output-schema listing tool, the description covers the essential question: what data comes back and how far it spans. Remaining gaps (ordering, exact year boundaries, response shape) are modest given the tool's simplicity and the fully documented parameter.

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?

Only one parameter exists and the schema documents it fully ('Subscriber token from /success'), so the schema does the heavy lifting. The description's 'PRO' hint loosely corroborates the token's subscription semantics but adds no new detail about how the token is passed or what happens if it is omitted (0 required parameters).

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 clear resource and scope: 'All holidays in the dataset (typically current + next year)'. An agent can tell this returns a full list rather than a per-date check, but the contrast with siblings like next_holidays is only implied, never stated. The leading 'PRO.' token is unexplained jargon that occupies the most prominent position without clarifying purpose.

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?

There is no explicit guidance on when to call this versus is_holiday or next_holidays. The scope phrase 'all holidays in the dataset' weakly implies a bulk-listing use case, but no alternatives, prerequisites, or exclusions are named.

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