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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so safety is covered. The description earns credit for disclosing that Islamic holidays are estimated pending reviewer verification and that delays are possible, which is real behavioral context beyond the annotations. It does not address response shape or pagination, so it sits above baseline but not at the top.

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 tight sentences, with the core resource and scope front-loaded before the estimation caveat. No filler, though the parenthetical status list is dense enough that it reads as a reference rather than prose.

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 output schema, the description does cover the meaningful parts of the return value (status taxonomy and sources) and warns about the estimation caveat. The residual gap is that it never explains what include_religious_scopes changes about the result set.

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 67 percent: country and include_religious_scopes are described inline, and year's bounds are enforced by the schema. The description restates country and year but adds nothing about include_religious_scopes, which is the one parameter whose effect (group-limited holidays such as faith, women, or public-sector) matters most for interpretation.

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 resource and scope: public holidays for a country and year, plus what each result carries (status values and sources). That distinguishes it from siblings like is_business_day or count_business_days, though it does not name any sibling explicitly.

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?

Usage is implied by the country+year framing, but there is no explicit guidance on when to call this instead of get_holiday_watch, is_business_day, or count_business_days, and no stated prerequisites.

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