things_duplicate_item

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

Annotations already signal a mutating, non-destructive, idempotent operation, and the description adds substantial behavioral context: the receipt contains the source ID rather than a new item ID, completion is not confirmed, and Things must be inspected before another request. This goes well beyond the structured hints.

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?

Four terse sentences are front-loaded with the action, then cover prerequisites, an edge case, response behavior, and follow-up instruction. There is no filler; each sentence earns its place.

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 mutation with an output schema, the description covers purpose, prerequisites, a key exclusion, response limitations, and post-call verification. It would be fully complete with explicit parameter-role explanations, but it is already adequate for an agent that can inspect the schema and sibling tools.

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 0%, so the description must compensate, but it only hints at parameters: 'to-do or project' maps to target.kind and 'current revision' maps to expectedRevision. It never explains requestId's role as an idempotency key or the meaning of the optional title field, leaving critical parameters underspecified.

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 opening sentence names the exact verb ('duplicate'), the target resource ('to-do or project'), and the mechanism ('documented URL command'). This makes the tool unambiguous and distinguishes it from siblings like create_item, update_item, and trash_item without needing to open their schemas.

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 gives actionable prerequisites ('Requires writes, current revision and the local Keychain URL token') and a firm exclusion ('Repeating items cannot be duplicated'). It stops short of explicitly naming alternatives such as create_item for new items, so the guidance is clear but not fully contrasted with sibling tools.

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