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

No annotations are provided, and the description only notes 'Browser-based tool' without disclosing how input is supplied, what the output format is, or any limitations. This leaves the agent guessing about invocation behavior.

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?

The description is a single sentence that front-loads the output categories and adds a concise parenthetical note about being browser-based. No wasted words.

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 no-parameter browser tool, the description covers the core purpose and outputs, but lacks explicit guidance on how a user's birth year is provided or when to invoke it relative to sibling tools, slightly limiting completeness.

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 tool has zero parameters, so the baseline is 4. The description adds context about the computations performed, which is sufficient given the empty 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 uses a specific verb '一括表示' (display all at once) and lists concrete outputs (age, Japanese calendar, zodiac, constellation, school years), clearly distinguishing it from the sibling date-calculator tool.

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?

The description implies use for birth-year-to-age/calendar conversion, but provides no explicit when-to-use guidance or comparisons to alternatives like date-calculator.

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