jp_shift_days

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

With no annotations, the description carries the full burden of behavioral disclosure. It does explain that business days skip weekends and Japanese public holidays and that negative values move backward, which is useful. However, it does not disclose what the tool returns (e.g., a date string) or how invalid dates are handled, leaving some ambiguity.

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 concise sentence that is front-loaded with the verb ('Move') and immediately states the core functionality. It avoids unnecessary words while including key details about business/calendar modes and negative values.

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 simple date-shifting tool, the description covers the primary behavior, the two modes, and the handling of negative values. However, it is missing an explicit statement of the return output (likely a date string) and does not mention edge cases like invalid input, but these gaps are minor given the tool's simplicity.

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 input schema provides parameter names and types but not the meaning of 'business' mode. The description adds crucial semantics by explaining that business days skip weekends and Japanese public holidays, and by clarifying that negative days move backward. This compensates for the 67% schema coverage.

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 clearly states the tool's function: 'Move a date forward or backward by N days' with specific details about business vs calendar days and negative values. This distinguishes it from sibling tools like jp_check_date (validating dates) or jp_count_days (counting between dates).

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 usage (shift a date by a number of days) and explains the mode options, but it does not explicitly state when to use this tool over siblings or provide exclusions. For example, it never mentions that this is for shifting dates, not for checking or counting.

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