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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds the useful default-mode behavior (next 10 from today), but says nothing about paging, ordering, or what 'make-up working days' means in the returned data. Solid but thin beyond the annotations.

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 sentences, no filler, with the primary resource statement first and the no-argument default behavior second. Every clause carries information an agent needs.

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 7-parameter, all-optional read tool with no output schema, the description covers the core invocation modes and the default case well. The main residual gap is the undocumented 'limit' parameter, which leaves the agent unsure how result truncation interacts with the 'next 10' default.

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 71% and the description reinforces year, from/to and the make-up-day concept, but the 'limit' parameter has no description anywhere in the schema or the description beyond min/max bounds. Region and include_government semantics live only in the schema. That puts it near the baseline rather than adding meaning.

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?

States a specific verb and resource ('List a country's public holidays') plus the scope modes (year, or from/to range, plus make-up working days). It's clear what the tool returns, though it never names the siblings (business_days, find_long_weekends, check_dates) it should be distinguished from.

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?

Explicitly describes the three invocation modes and what happens when neither year nor range is supplied ('lists the next 10 holidays from today in that country'). It lacks a when-not clause pointing to business_days or find_long_weekends for related date queries, so routing depends on the agent inferring from names.

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