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

With no annotations, the description carries the full burden. It does add genuine behavioral context that structured fields lack: results come with official sources and checked dates, and uncovered years return unknown rather than fabricated data. It omits return shape, behavior with conflicting/absent parameters, and any failure modes.

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?

A single front-loaded sentence with the lookup modes stated first and the provenance/coverage caveat second. No filler, nothing repeated from the schema.

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 two-parameter, no-annotation, no-output-schema tool, the description covers purpose, provenance and coverage limits adequately. But with zero required parameters, the agent is left guessing what an empty call does, so the definition is not fully self-sufficient.

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%, so the schema already documents both parameters and their formats. The description still adds meaning by framing year and date as alternative lookup modes, which the schema does not express; it does not address precedence when both are provided.

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 pairs a specific verb ("Find") with a specific resource ("Victorian public holidays") and states the two lookup modes, year or exact date. Sibling tools are all unrelated topical assistants, so no differentiation is needed, though none is offered 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?

"by year or exact date" implies the two calling modes but never states when to prefer one over the other, nor what happens if both are supplied or neither is supplied (both parameters are optional). Usage is inferable but not spelled out.

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