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

No annotations are provided, so the description carries the full burden of behavioral disclosure, and it discloses nothing — no return value, no side effects, no implicit inputs, no edge cases. A tool named 'year-start' could reasonably be expected to compute the first day of the year, but nothing in the description confirms this or explains what happens.

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?

While nominally short, this is under-specification, not conciseness. The phrase 'Year Start: Year Start' contains only redundancy and contains no information that earns its place. Minimal length is not a virtue when it conveys nothing.

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?

Given 0 parameters, no annotations, no output schema, and a meaningless description, an agent has no way to understand what this tool computes or what it returns. Even a trivially simple tool needs at least one sentence defining its behavior and output. This is completely inadequate.

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?

The schema has 0 parameters and 100% coverage, so there is nothing structurally missing regarding inputs. However, the description adds zero semantic context about implicit inputs the tool might rely on (e.g. current date/time), which an agent would need to know. Baseline 3 is appropriate.

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 'Year Start: Year Start' is a pure tautology that restates the tool name without any verb or resource. It gives no indication of what operation is performed — does it return a date, a boolean, or a formatted string? The meaning is entirely ambiguous and there is no differentiation from siblings like x402-year-end, x402-quarter-start, or x402-month-start.

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?

There is zero guidance on when to use this tool versus any alternative. No context, no exclusions, no mention of related sibling tools that might be better suited for related date calculations. The agent is left with no basis to choose this tool over the hundreds of siblings.

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