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

Annotations already signal readOnlyHint=false and idempotentHint=true. The description adds useful behavioral context: the returned link leads to a page where the user sees the summary, may add a building photo, accepts terms, and pays at an external operator, while MCP itself never handles card data. No contradiction with annotations.

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 no filler: the first states the purpose, the second summarizes the payment page flow, and the third gives a hard precondition and a security note. The most important usage constraint is highlighted in caps for emphasis.

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 no output schema, the description provides the return value, the precondition for invocation, the user-facing flow, and a security boundary. Nothing essential for an agent to invoke it correctly is missing.

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 documents both parameters at 100% coverage, including that order_id comes from create_certificate_order and that access_token is returned once and must be kept secret. The description does not add parameter-level detail, but it does not need to because the schema covers it.

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 action and object: returns a secure payment-page link for a complete order. This clearly distinguishes it from sibling tools that deal with certificates, drafts, documents, or pricing, and it makes clear the tool does not execute a payment itself.

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 explicitly states when to call the tool: only after showing the user the price and receiving explicit consent. It also adds a relevant boundary by stating that MCP never accepts card data, giving the agent a clear safety-context rule.

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