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

Goes well beyond the annotations: discloses the exact price (EUR 9.90), that the MCP tool never charges, the external payment channel, the human-authorization requirement, the idempotent reuse pattern for polling, and an explicit trust caveat about website-derived evidence. These are precisely the facts an agent needs before committing a paid, mutating action.

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?

Front-loaded with the deliverable, then the payment/auth constraints, then the polling rule and trust warning — a logical order with no filler sentences. Dense jargon ('MPP-compatible wallet', 'canonical HTTPS API endpoint') costs some readability but not length.

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 an async, paid, two-step workflow with no output schema, the description covers cost, authorization, key reuse and trust. It only gestures at the response ('the returned canonical HTTPS API endpoint') without describing the full return shape or polling cadence, which leaves a small gap since no output schema exists.

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 67% with 'url' and 'idempotency_key' already well documented; the description adds cross-call semantics by telling the agent to reuse the same private order key across payment and polling. Only 'locale' remains undocumented anywhere, a minor gap.

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 ('Prepare one paid public website analysis') and enumerates the deliverable's parts (finding, evidence, why it matters, next step). The verb 'prepare' is slightly ambiguous about whether the analysis is executed now or later, but the following sentences resolve that it creates an order plus a payment endpoint.

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?

Explicitly sets the operational context: the tool itself never charges, payment must be authorized separately via an MPP-compatible wallet at the returned endpoint, and a human/operator must approve. It also describes the follow-up flow (reuse the key to poll). No sibling alternatives exist to route against, so nothing more is required.

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