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

The description discloses that the tool creates a payment link rather than directly granting access, includes cost and tax, and explains the automated versus manual checkout URL hand-off. It also describes the post-payment retry with the same API key and Idempotency-Key. The annotations already signal non-read, non-idempotent behavior, and the description adds practical flow details without contradiction.

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?

Four sentences, each with a distinct purpose: the action, the trigger, the execution path, and the post-payment step. There is no redundancy and the core verb and price are front-loaded.

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 zero-parameter tool with annotations and sibling context, the description covers the trigger, cost, tax, checkout URL hand-off, automation capability, and what to do after payment. No output schema exists, but the description gives enough actionable information for an agent to invoke 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?

The input schema has zero parameters, so there are no parameter meanings for the description to add; baseline for zero-parameter tools is 4. The description usefully references the agent API key and Idempotency-Key as context for the retry flow, though these are not schema parameters.

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 action and object: it creates a Stripe payment link for one MarginGlow AI Signal at EUR 2. This clearly distinguishes it from the sibling analysis and access-check tools.

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?

It explicitly says to use this tool when analyse_small_business_opportunities reports no Signal credits remain, and it gives post-payment retry instructions. It does not explicitly state when not to use it, but the trigger condition implies that if credits remain, this purchase is not needed.

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