fund_transfer

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

The description adds the PSD2 regulatory limitation beyond the annotations, which already indicate a destructive, non-read-only operation. However, it doesn't disclose the financial consequences (e.g., irreversible deduction from balance) or that the transfer must be in a fundable state. No contradiction with annotations.

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 sentences, front-loaded with the action, and the caveat is clearly separated. Every word earns its place, making it highly concise and scannable.

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 two-parameter tool with no output schema, the description is adequate but leaves gaps: it doesn't state prerequisites (transfer must exist, be in a fundable state), or what happens upon success/failure. The PSD2 note is useful, but overall completeness is average.

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% with minimal descriptions ('Profile ID', 'Transfer ID'). The tool description adds no extra meaning about how profileId and transferId relate to the funding operation, so it falls at the baseline for high schema coverage.

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 action ('Fund a transfer') and the resource ('your Wise balance'). It distinguishes from sibling tools like create_transfer by focusing on funding an existing transfer, though it doesn't explicitly say the transfer must already exist.

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 PSD2 note gives a specific when-not-to-use condition for EU/UK personal tokens, but there is no explicit guidance on when to use this tool vs alternatives (e.g., after create_transfer, before the transfer is executed). The context is implied at best.

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