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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true), so the main remaining question is side effects. The description usefully clarifies that 'Nothing is charged until they complete it', which is real behavioral context beyond the annotations, but it does not explain the non-idempotent behavior or link expiry, so it stays at a solid 3.

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?

Two short sentences with the outcome front-loaded and the reassurance about no immediate charge placed after it. Nothing is padded, though it is arguably too terse given the undocumented parameters.

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 link-generation tool with no output schema, the description covers what is produced and the key side-effect fact. However, it omits when to call it, what 'product' accepts, and whether the returned link is single-use or expiring, leaving gaps an agent would need filled.

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 0%, so the description must carry parameter meaning. The pricing phrase '50p per device per month' implicitly clarifies that 'devices' drives cost, but the required 'email' and the 'product' parameter are left entirely undefined in both schema and description, so the compensation is only partial.

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?

States a specific verb and resource ('Returns a secure Stripe link') plus the business context (50p per device per month subscription), which is far more concrete than the title alone. It does not name a sibling to differentiate against, but no sibling in the list is a near-duplicate of this billing concern, so ambiguity risk is low.

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 implies the scenario (a person needs to add a card) but never states when to call this versus the other setup/account tools like sebbi_create_account or sebbi_gateway_setup. There are no prerequisites, no exclusions, and no explicit when-to-use guidance.

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