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

With no annotations provided, the description carries the full burden, and it does disclose the scope of returned content (holiday status, next holiday, next long weekend, upcoming list). However, it says nothing about data source, region/timezone, refresh behavior, or that this is a passive read with no side effects.

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?

A single compact sentence that packs four distinct output facets without filler. It is dense but slightly list-like rather than front-loaded around a core purpose statement.

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?

With no annotations, no output schema, and no parameters, the description is the entire contract, and it does describe the returned facets. Yet it omits regional scope, date format, and timezone, which matter for a holiday-calendar tool, leaving gaps an agent cannot fill from structured fields.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate. Baseline 4 applies; no parameter semantics are required.

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 enumerates a concrete set of returned resources: today's holiday status, the next national holiday, the next long weekend with start/end dates and day count, and the upcoming holiday list. The purpose is clear, but the definition never distinguishes itself from the overlapping siblings is_holiday and get_holidays, so it falls short of a 5.

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 when-to-use, when-not-to-use, or alternative routing guidance at all, even though is_holiday (today's status) and get_holidays (upcoming list) clearly overlap with what this tool returns. An agent must guess which of the three to call.

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