paypal_fee_calculator

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

With no annotations provided, the description carries the full behavioral disclosure burden. It does disclose the core fee formulas, which is useful behavioral information. However, it does not mention what the tool returns (fee amount vs. total), currency assumptions, rounding behavior, or how the isMicropayment flag affects the calculation beyond the rate. This is partial transparency.

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 a single concise sentence that front-loads the most important functional information: the fee rate formulas. There is no wasted wording, and every piece of content adds value for an agent trying to calculate a PayPal fee.

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?

This is a simple calculator with two parameters and no output schema, so the description is not required to be extensive. However, it lacks explicit return-value semantics, currency/unit clarification, and clear parameter-to-rate mapping. The core rate information is present, making it barely adequate for correct invocation, but not fully complete.

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 for the bare number/boolean schema. It explains the two rate tiers and implies that isMicropayment selects between them, adding meaning beyond the schema. However, it does not explicitly map 'domestic 2.99%+$0.30' to amount/isMicropayment, nor does it clarify units or default behavior for isMicropayment.

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 communicates that this tool deals with PayPal fees and specifies the domestic and micropayment rate structures, which makes the resource clear. It lacks an explicit verb like 'calculates', but the tool name and rates make the purpose inferable. It does not explicitly differentiate from sibling fee calculators beyond the name, so it falls short of a 5.

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 implies usage for PayPal domestic or micropayment fee calculations, but it does not explicitly say when to use this tool versus alternatives like etsy_fee_calculator or stripe_fee_calculator. It also does not state exclusions such as international transactions. The usage context is only implied by the name and the two rate categories.

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