Execute Villager Trade

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

The annotations already indicate this is a non-read-only, non-idempotent operation with no destructive world effects. The description adds valuable behavioral context by stating the stateful prerequisite (currently open villager) and enumerating specific error scenarios. It also states the return format as a simple message. That said, it does not explicitly mention that the trade consumes or produces items, which would further clarify the change in state.

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, with the action and precondition in the first sentence, followed by a clear Returns/Errors structure. No filler or redundancy; every clause adds operational information.

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?

Given the lack of an output schema, the description still covers the return value as { message } and lists common failure modes. The tool's simplicity and the annotations reduce the need for extensive explanation. It could be more complete by describing the inventory effect of a trade, but overall it provides sufficient context for basic usage.

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 schema documents the 'times' parameter with a description and range, but 'trade_index' has no schema-level description. The description's 'by trade index' provides minimal additional meaning, and the error list mentions 'invalid trade index', reinforcing validation. However, it does not clarify whether the index is zero-based or one-based, and it adds little beyond what the parameter name implies.

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 the specific verb 'Executes' with the resource 'trade' and includes the precondition of an open villager, clearly distinguishing it from sibling tools like minecraft_open_villager or minecraft_use_held_item. It also mentions the trade index parameter directly. This leaves no ambiguity about the tool's function.

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 explicitly states 'call minecraft_open_villager first', which is a direct prerequisite. It also lists error conditions such as 'no villager open' and 'missing required items', informing the agent when the tool will fail. However, it does not discuss alternatives or exclusion cases beyond the prerequisite, so it lacks some of the comparative guidance seen in higher-scoring examples.

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