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

With no annotations, the description carries the full load, and it does disclose something genuinely useful in the credit cost and the gov.uk data source. It does not state that this is a read-only lookup or what the results look like, so the safety profile and response shape remain implicit.

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 fragments with the subject front-loaded and the cost caveat parenthesized at the end. Nothing is wasted, though the telegraphic style leaves the description thin rather than rich.

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 simple two-param lookup with no output schema and no annotations, the description is adequate but leaves real gaps. Both params are optional, yet there is no mention of what happens when year or division is omitted, and no hint of the returned fields.

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%, with 'year' documented as YYYY and 'division' listing the three valid values, so the schema does the heavy lifting. The phrase 'by division and year' only restates what the params already convey, adding no syntax or default information.

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: UK bank holidays by division and year, sourced from gov.uk. The 'UK' qualifier implicitly separates it from the generic public_holidays sibling, but that differentiation is never made explicit.

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?

No guidance on when to use this versus public_holidays, working_days, or holiday_entitlement, which are the obvious adjacent tools. The agent must infer that this is the UK-specific path.

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