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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. Beyond that, the description discloses a hard server-side failure mode ('e-Courier rejects anything else' for >10-day ranges) that an agent must respect to avoid errors. It says nothing about result volume, pagination or truncation limits, which is the remaining gap.

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 compact sentences front-load the required date-range constraint before the optional filters, which is the right ordering. The dangling 'GetPayment.' fragment is unexplained and earns little place, but overall there is minimal waste.

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 read-only filter/list tool with full schema coverage and no output schema, an agent has everything needed: required params, the enforced 10-day ceiling, and optional narrowing fields. Return-value description is not required here, so nothing essential is missing.

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 100%, so the schema already documents every parameter including the 10-day end-date rule; the description mainly restates which params are required and which are optional narrowing filters. It does not clarify the non-obvious interaction that payment_id still requires a date range, nor what the trailing 'GetPayment' label signifies. Baseline 3 is appropriate.

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 and resource: customer payments received within a payment date range, plus the three optional narrowing filters. It does not name any sibling (e.g. ecourier_list_invoices) to disambiguate, so the agent still has to infer the boundary between payments and invoices, but the resource itself is unambiguous.

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?

Gives explicit preconditions for use: both date bounds are required and the window must be at most 10 days, and it explains what the optional filters do. It stops short of naming alternatives or when-not-to-use cases (e.g. when to prefer ecourier_list_invoices), so it is clear context without routing.

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