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

Beyond the annotations, it discloses the paid nature of the call, a concrete price range ($0.0015 to $0.6 USDC), the payment rail (x402, USDC on Base/Solana/Polygon/Arbitrum), and that x402-capable MCP clients settle automatically. It also notes the example input is a free sample, which is operationally important context an agent cannot get from the schema or the hints.

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?

It is front-loaded with the invocation example, then the prerequisite, then cost mechanics — a sensible order with little filler. The payment sentence is dense but each clause (price, chain, auto-pay) carries distinct information an agent needs before committing funds.

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 nested-input dispatcher with no output schema, the definition covers invocation, prerequisites, and cost/auth requirements thoroughly. It never indicates what a successful response looks like or how errors and payment failures surface, which is the main remaining gap.

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 already 100%, so the baseline is 3, but the description adds real meaning: it shows the exact JSON shape, ties 'service' to find_service output, and ties 'input' to that service's own input_schema. That resolves the nested-object ambiguity the schema alone only gestures at.

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 verb and resource ("Run any agentsvc.io service by name with its input") and backs it with a concrete payload example, so the dispatcher nature is unambiguous. It is clearly separable from find_service, which is positioned as the discovery step rather than the execution step.

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 gives an explicit prerequisite: "Use find_service first to get the name and input schema," which tells the agent the correct call order. It does not say when to prefer a sibling direct-call tool (e.g. web_scrape, translate) over this generic dispatcher, leaving that choice to inference.

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