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

Goes well beyond the annotations: discloses the 11 USDG minimum, cap enforcement, fresh-price requirement, pre-flight simulation against the latest block, and explicit refusal on revert. 'Never signs or sends' reinforces and explains readOnlyHint=true rather than contradicting it, since unsigned transaction data is returned.

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?

Two dense sentences, front-loaded with the action and followed by constraints and return shape. No filler and nothing restated from the title.

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?

Even without an output schema, the description names the returned fields (to, data, value, gas) and the failure mode (refused if simulation reverts), so an agent knows both what it gets back and how the call can fail.

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 coverage is 100%, so owner, market, collateral, and mintTokens are already documented with examples. The description adds only the 11 USDG floor for collateral and mentions 'tokens' generically for mintTokens, which is marginal value beyond the schema.

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?

States a specific verb+resource ('Open or add to a position') and enumerates the composed steps (USDG approval, then create with collateral/tokens). The phrase 'for the user's own wallet' implicitly separates it from the prepare_mandate_create_position siblings, but no sibling is named explicitly.

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?

Usage is implied through preconditions (11 USDG minimum for new positions, 'if needed' approval) and the ownership scoping, but the description never says when to choose this over prepare_mandate_create_position, quote_position, or get_position when deciding whether to open versus inspect a position.

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