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

With no annotations, the description carries the full behavioral burden. It usefully discloses the output shape via inline examples, but says nothing about the reference point (assumed 'now'), timezone handling, or how future dates are rendered. Adequate but incomplete for a zero-annotation tool.

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 short sentences, output examples front-loaded after the verb phrase. Efficient, though 'Provide date or value' is slightly redundant given 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?

No output schema and no annotations, so the description must stand alone; it does explain the return format via examples, but omits reference-time and timezone assumptions that matter for relative-time computation. Minimally 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 both parameters are already documented in the schema; baseline is 3. The line 'Provide date or value' gestures at the alternation between the two params but does not clarify whether one is an alias for the other or which takes precedence, adding little beyond the schema.

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 states a specific verb (format) and resource (a date as a relative time string) and gives concrete output examples ('3 days ago', 'just now'), so an agent knows exactly what it produces. It does not, however, differentiate itself from close siblings like x402-relative-time or x402-days-since.

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 when-to-use, when-not-to-use, or alternative-tool guidance is offered. In an ecosystem with x402-relative-time and x402-days-since, the absence of routing guidance is a real gap.

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