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

With no annotations provided, the description carries the full burden of behavioral disclosure, and it discloses nothing whatsoever — no mention of what the tool returns, no format expectations, no edge-case behavior. The description is empty of behavioral content.

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?

At four words, this is severely under-specified rather than concise. Every sentence should earn its place, and this one carries zero useful information — it merely echoes the tool name. This is not economy of prose; it is absence of content.

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 single-parameter calculator with no annotations and no output schema, the description is the only source of guidance, and it explains neither the expected date format, the meaning of the output, nor how this differs from x402-zodiac-sign. The tool is completely inadequate as an invocation aid.

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 description coverage is 100%, so the schema already documents the single 'date' parameter ('Date to process'), warranting the baseline of 3. The description adds no parameter context beyond the schema, and 'Date to process' remains vague about format, but per the rubric the schema carries this dimension at baseline.

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 'Chinese Zodiac: Chinese Zodiac' is a pure tautology that restates the tool name. It contains no verb, no resource, and no statement of what the tool computes (e.g., the zodiac animal for a date or year). An agent reading this learns nothing it didn't already know from the tool name.

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 no guidance on when to use this tool. Notably, siblings like x402-zodiac-sign (Western zodiac) and x402-chinese-new-year exist, and the description offers no way to distinguish when to pick this tool over them. The name provides only a weak implicit hint; no exclusions or alternatives are mentioned.

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