Mark bill paid

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

Annotations already convey readOnlyHint=false and idempotentHint=true, so the safety profile is known. The description adds meaningful side-effect context beyond the annotations: marking the bill paid also creates the next bill if it recurs. This is important behavior an agent would not otherwise know from the schema or annotations.

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 two short sentences with the main action and side effect front-loaded. The second sentence ('Needs the bill name or id') is somewhat redundant with the schema's required parameter, but it is concise and helps the agent understand the primary input without opening the schema.

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 a 100%-covered input schema, an output schema, and annotations covering idempotency, the description is nearly complete. It adds the one non-obvious behavior (recurrence creation) that the structure does not already expose. It doesn't cover every edge case, but nothing critical is missing for a correct call.

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 parameter descriptions already handle semantics fully. The description barely adds parameter-specific meaning beyond echoing that the bill can be identified by name or id, which is already documented in the schema. Baseline 3 applies.

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 states a specific verb and resource: it marks a bill as paid and handles recurrence by creating the next bill. This distinguishes it from siblings like add_bill, update_bill, or get_bill, so an agent can tell when this tool is the right one.

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 intended use is implied by the action ('mark a bill as paid'), and the description mentions the required input ('bill name or id'). However, it does not explicitly address when to prefer this over update_bill or other bill-related siblings, nor does it state when not to use it.

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