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

With no annotations, the description carries the full burden of explaining behavior. It details the included data (weekday, national/regional scope, weekend flag, school holiday periods) and the source, but does not mention error handling, potential limits, pagination, or any side effects. For a simple read operation, this is adequate but not exhaustive.

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?

The description is a single, well-structured sentence that front-loads the key output (all public holidays and school holiday periods) and includes clarifying attributes in parentheses. It is concise and free of unnecessary detail.

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 the tool's simplicity and lack of an output schema, the description sufficiently conveys what the response contains (attribute details for holidays and school periods) and identifies the data source. It does not describe the output format, but for this use case the description provides enough context for an agent to understand what to expect.

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 schema covers 100% of the parameters with descriptions, including examples for region and defaults for year/locale. The tool description itself does not add additional parameter semantics beyond the schema, so the baseline of 3 applies.

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 clearly states the tool's purpose: returning all public holidays (with specified attributes) and school holiday periods for a given region and year. It identifies the specific resource and scope, distinguishing it from siblings like best_bridge_days (which compute bridge days) and plan_vacation (which suggests vacation plans).

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?

The description implies that this tool is for retrieving raw holiday data for a region and year, but it does not explicitly state when to use it versus siblings such as best_bridge_days or plan_vacation. No direct mention of alternatives or exclusions is provided, though the tool's specificity makes the use case reasonably clear.

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