copy_day

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

The description explicitly states 'Additive -- does not remove existing entries on the destination date,' which adds meaningful behavioral context beyond the annotations. The annotations already indicate non-destructive behavior, but the description clarifies the exact merge semantics and what side effects will not occur.

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 compact and front-loaded with the primary purpose, followed by the key additive behavior and a concise parameter explanation. Every sentence conveys essential information without repetition or filler.

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 tool with one optional parameter, a clear source/destination model, an additive safety note, and an output schema, the description is complete. An agent has enough information to invoke the tool correctly without additional missing context.

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?

Although schema description coverage is 0%, the description fully documents the only parameter: date as YYYY-MM-DD with a default of today. It also clarifies that date is the destination date, which adds meaning beyond the raw schema definition.

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 verb 'Copy' and the resource 'all diary entries from the previous day' to a specified destination date. This is a specific, unambiguous operation that distinguishes copy_day from the provided siblings, none of which describe copying diary entries.

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 intended use is implied by the core statement 'Copy all diary entries from the previous day to the given date.' However, the description does not explicitly discuss when to prefer this tool over alternatives or mention any exclusions, so usage guidance is only implicit rather than clearly framed.

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