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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds the return contract ({rules: [...], count: N}) and the default 'show all' behavior for is_active, which is useful beyond the annotations. It omits ordering/pagination but that is minor for this simple list.

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 action is stated in the first sentence, and the Args/Returns sections are compact and scannable. There is no filler or repeated schema boilerplate.

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 one-optional-parameter read-only list tool with annotations, the description covers the action, filter semantics, default behavior, and return shape. Nothing needed to call it correctly 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 0%, so the description carries the full burden. It explains that is_active filters by active/inactive and that the default is to show all, giving the parameter meaningful behavior rather than just a nullable boolean.

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 names a specific operation and resource: it lists the user's debt payment rules, which distinguishes it from rule mutation tools (create/update/delete_debt_payment_rule) and from list_debt_payments. The scope ('the user's') is explicit.

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 listing intent is clear from the verb and resource, but the description gives no explicit when-to-use or when-not-to-use guidance and names no alternatives. An agent would infer use from the name rather than being told.

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