Free, no key, nothing stored. The Swiss public holidays of a year with their weekday: the four every canton keeps (national) and the ones most cantons keep (most_cantons). Cantonal and communal holidays are not listed; the canton's list decides.
| Name | Required | Description | Default |
|---|---|---|---|
| year | No | the year, default: this year |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new context beyond the annotations: no API key, no cost, and nothing stored, which reassures the agent about side effects and auth requirements.
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 dense sentences with the cost/privacy qualifier front-loaded and the return scope immediately after. It is efficient and front-loaded, though the fragment 'Free, no key, nothing stored' reads telegraphically rather than as a polished lead.
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?
Despite no output schema, the description fully characterizes the return content (holidays with weekday, split into national and most_cantons sets) and its exclusions. For a single-optional-parameter lookup tool, nothing needed to call it correctly is missing.
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% and the single parameter is documented in-schema as 'the year, default: this year'. The description only restates 'of a year' and adds no format, range, or default nuance beyond the schema, so the baseline 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 names the exact resource (Swiss public holidays for a given year with weekday) and draws a precise scope boundary: the four national holidays plus the most_cantons set, with cantonal/communal holidays explicitly excluded. An agent knows exactly what comes back without opening the schema, and no sibling overlaps this domain.
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?
It states constraints (free, no key, no storage; cantonal/communal lists excluded) which implicitly tells the agent when this tool is sufficient, but there is no explicit when-to-use versus when-not framing or named alternative. With no comparable sibling tools, usage is implied rather than spelled out.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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