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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds minimal behavioral context beyond the schema, such as the scoping to canton/municipality for school holidays. It does not disclose return format, pagination, or edge cases, but with annotations carrying the safety burden, this is adequate.

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, front-loaded sentence that immediately communicates the tool's purpose. Every word earns its place, with no filler or repetition of schema details. The title and description together are compact and efficient.

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 presence of an output schema, annotations, and a fully documented input schema, the description is sufficient for an agent to select and invoke the tool correctly. It does not explain that place is optional for public holidays or that language affects output, but those details are already in the schema. The only minor gap is not clarifying that 'public holidays' may not require a place, but this is inferable from the schema's default null.

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 all four parameters (kind, year, place, language) already have meaningful descriptions. The tool description does not add any semantic detail beyond the schema—it only restates the general topic. A baseline of 3 is appropriate when the schema fully documents 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 specific resource ('School holidays by canton or municipality, or public holidays') and a time scope ('for a year'). It clearly distinguishes this tool from siblings like federal_votes or public_transport by naming the exact domain. The verb is implied but unambiguous, and the title reinforces the 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?

The description implies usage: if an agent needs school or public holidays for a Swiss location and year, this is the tool. However, it does not explicitly state when to use it over alternatives, nor does it mention any exclusions or conditions (e.g., 'use swiss_place_info for place details'). The guidance is present only by inference from the tool's domain.

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