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

Annotations already mark this as read-only and non-destructive. The description adds useful behavioral details beyond the schema: the tool returns a verdict with a percentage gap, accepts player-style phrasing including Russian, infers the game when omitted, and refuses mixed-game trades because their scales are incompatible.

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?

Three compact sentences deliver the core behavior, output, input style, and a key constraint. Examples are illustrative without bloating the description, and the most important information about the verdict comes first.

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, read-only evaluation tool with three well-documented parameters and no output schema, the description covers input format, language support, game inference, cross-game refusal, and the nature of the result. The only minor omission is an exact example of the output structure, but the stated 'win, fair or lose' plus percentage gap is sufficient for an agent to invoke it correctly.

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 100%, so each parameter is already documented. The description still adds meaningful context: the 'game' parameter is optional and may be inferred from item names, and give/get should use comma-separated player-style phrasing rather than internal item IDs. The Russian-language examples further clarify accepted input.

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 states a specific verb and resource: it 'adds up both sides of a proposed trade' and returns 'win, fair or lose' with the percentage gap. This clearly differentiates check_trade from the sibling tools get_value, list_values, and search_items, which are about looking up values or lists rather than evaluating a trade.

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 clarifies when the tool applies: a single game's trade, phrased the way a player would say it, and it explicitly says mixed-game trades are refused. It does not name alternative sibling tools directly, but the trade-specific framing and constraints make the intended use clear.

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