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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive behavior. The description goes well beyond this by stating there is no payment path, no store, no scheduler, no custody, and that the lane refuses based on its own kill file and lane state, plus the cancellation behavior.

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?

Although the description is long, every sentence earns its place by adding a distinct behavioral or usage fact. The core function is front-loaded, and the additional assurances about no charge, no token, no return, and no custody are directly relevant to correct invocation and expectation-setting.

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?

The description is complete given the rich schema, output schema, and annotations. It covers argument combinations, no-argument behavior, the absence of payment paths, Standing semantics, and cancellation outcomes, leaving an agent with everything needed to call the tool correctly.

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 baseline is 3, but the description adds meaningful semantics beyond the schema: amount range and whole-dollar constraint, period choices, place-as-coordinate-cluster, wallet being the subscriber's own address used for receipts and Standing, and the opt-in being preference-only with no token custody.

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 function: it returns a plan showing exactly which open, unfunded packets at a named place a subscription amount would back, in the board's order and at the board's prices. It also explicitly distinguishes this from a live charge or status tool by emphasizing that nothing charges and it is read-only.

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 gives clear context on when to call the tool and even notes the no-argument call for the product and ladder. It does not explicitly name sibling tools or state when not to use them, but the usage scope is well-defined and easy to apply.

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