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

Annotations already declare read-only, idempotent, closed-world behavior, and the description adds materially new context: the data_confidence vocabulary, estimated_items[], official source URLs, and data_version. That is exactly the kind of behavioral detail annotations cannot convey.

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?

Front-loads the answer (what it returns) in the first clause, then usage, then example, then response contract. Dense but every sentence carries information; the parenthetical confidence glossary is justified because agents need it to interpret results.

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 an output schema existing, the description still surfaces the fields that change how an agent phrases its answer (confidence level, estimates, version). Combined with rich annotations and fully documented params, nothing needed for correct invocation or interpretation 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 enum fields are well documented, so the baseline is 3; the description goes further by demonstrating a realistic from_date/emirate/sector combination and what each implies in the output. It doesn't restate the default semantics of emirate='federal', hence a 4 rather than 5.

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 ('Return the next public holiday on or after a date'), names the scoping dimensions (emirate/sector) and enumerates the returned fields. The 'next' framing cleanly separates it from list_holidays in the sibling set.

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 says when to use it ('when is the next long weekend / holiday' questions, warning about upcoming closures) and supplies a worked example call with a concrete result. It doesn't name an alternative sibling or state exclusions, which keeps it short of a 5.

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