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

With no annotations, the description carries the behavioral burden. It discloses the JWT lifetime (15-minute), the dry-mode nature of sandbox, and the spend/settle restriction. It omits side effects or failure conditions, but the most important operational constraints are stated.

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?

Three sentences with a clear front-loaded action. The only slightly cryptic element is the 'Cash face' URL at the end, but it is not redundant filler and the core guidance is compact.

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 two-parameter tool with a 100% documented schema, the description covers the live/sandbox distinction and key constraints. There is no output schema, but the tool's output (a JWT) is reasonably implied. The description is sufficiently complete for correct invocation.

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. The description adds value by explaining how to select api_key: vaulted ar_ from register for live seats vs the public sandbox key when the environment variable is set. The schema documents scopes behavior, but the description clarifies the key selection logic beyond the schema.

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 opens with a specific verb and object: 'Mint a 15-minute rider JWT.' This clearly distinguishes the tool from siblings like verify_rider (verification) and register (account creation) by identifying the exact artifact and its time-to-live.

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 explicit guidance on when to use live vs sandbox credentials based on whether RIDER_SANDBOX_API_KEY is set, and warns that the sandbox cannot spend or complete funded settle. However, it does not explicitly compare this tool with alternative tools or 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.