l402-store-token

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

The description adds behavioral context beyond the idempotentHint annotation by stating the token is persistently 'stored as a credential' and that this makes subsequent l402-fetch calls authenticated. It does not contradict the annotations; the readOnlyHint=false aligns with the mutation implied by 'Store.'

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 sentences with no wasted words. It front-loads the core action, then provides the usage trigger and downstream benefit, making it easy for an agent to parse quickly.

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 two-parameter store operation, the description covers what the token is, where it comes from, and why it matters. It does not describe the return value or error behavior, but given the simple side-effect model and the idempotentHint annotation, this is a minor gap rather than a blocking omission.

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?

The input schema already has 100% coverage with clear descriptions for both parameters, including the token format 'macaroon:preimage'. The description reinforces the token format and purpose but does not add meaningfully beyond the schema's parameter descriptions.

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: 'Store an L402 token (macaroon:preimage) obtained from a payment page.' It also clarifies the token's role as a stored credential for authenticating subsequent l402-fetch calls, making the purpose unambiguous and distinguishable from sibling tools like l402-credentials or l402-fetch.

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 an explicit trigger: 'Use this when a user pastes back a token from a toll-booth payment page.' It also explains the downstream effect by noting the token is stored for later l402-fetch authentication, but it does not explicitly mention alternatives or cases where this tool should not be used.

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