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

With no annotations, the description carries the burden. It does disclose the default result limit ('up to 1000 most recent payments if no filters are applied') and the credential requirement (bo_key), which is helpful. However, it doesn't mention pagination, response format, error behavior, or whether filters are combined (AND semantics). These are notable gaps for a list operation, but the disclosed information adds some value.

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 with no filler: the first identifies the action, resource, and credential; the second lists filters and default behavior. It's front-loaded with the core purpose and scannable for an agent.

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 list tool with 100% schema coverage, the description covers the return limit and filter scope. Missing: whether multiple filters are combined, exact response structure, and any note on date range boundaries. Those are common expectations for a list endpoint and not fully disclosed, but the description is adequate for the tool's complexity.

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 the schema documents all parameters. The description adds the default behavior context and briefly restates filter categories, but doesn't add deeper semantics beyond the schema. Baseline 3 is appropriate because the schema does the heavy lifting; the description's summary of filter types doesn't conflict with but doesn't enrich 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 clear verb ('Lists') with a specific resource ('completed payments') and the credential used (Backoffice Key). It also distinguishes itself from siblings like mbway_request_payment and multibanco_create_reference by indicating it's a read/list operation, not a payment creation tool. The filter list and default behavior (1000 most recent) add specificity beyond the name alone.

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 says it filters by payment method, date range, order ID, reference or request ID, which implies read-after-create usage or listing past completed payments. It doesn't explicitly say 'use this instead of create/payment tools when listing completed payments', but the contrast with sibling create/status tools is clear from the description's wording. There are no explicit exclusions or alternative routing, so a 4 rather than 5.

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