xendit-mcp

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

No annotations are provided, so the description carries the full burden. It mentions 'optional filters' and a specific use case for 'reference_id', but lacks critical behavioral details: it doesn't specify whether this is a read-only operation, what permissions are needed, if there are rate limits, pagination behavior (beyond the 'limit' parameter in schema), or what the output looks like. For a list tool with no annotation coverage, this is inadequate.

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 extremely concise with two sentences: the first states the core purpose, and the second provides a specific usage tip. Every word earns its place, and it's front-loaded with the main action. No wasted verbiage.

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 complexity (4 parameters, no annotations, no output schema), the description is incomplete. It lacks details on behavioral traits, most parameter meanings, output format, and differentiation from siblings. While concise, it doesn't provide enough context for an agent to use the tool effectively without additional assumptions.

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. It only adds meaning for 'reference_id' ('for CareNow loan ID lookups'), leaving the other three parameters (paymentMethodId, customerId, limit) undocumented. The description does not explain what these parameters do, their formats, or how they interact, failing to adequately cover the parameter semantics 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?

The description clearly states the tool's purpose: 'List payment requests with optional filters.' It specifies the verb ('List') and resource ('payment requests'), and distinguishes it from siblings like 'xendit_get_payment_request' (singular) by implying a bulk retrieval. However, it doesn't explicitly differentiate from other list tools (e.g., 'xendit_list_invoices'), so it's not a perfect 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 provides some usage guidance: 'Use reference_id for CareNow loan ID lookups.' This gives a specific use case, but it doesn't explain when to use this tool versus alternatives like 'xendit_list_transactions' or 'xendit_get_payment_request', nor does it mention prerequisites or exclusions. The guidance is implied rather than explicit.

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