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

With no annotations, the description carries the full behavioral burden. It usefully discloses the cost and payment rail ($0.005 USDC via x402 on Base mainnet), which implies a paid, likely on-chain transaction with side effects, but it never states what "structurally validate" actually checks, whether payment is charged on failure, or what the result looks like.

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, front-loaded sentences with no filler: the purpose first, then the price. It is efficient, though its brevity borders on under-specification rather than true economy.

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 five-parameter tool with no output schema, no annotations, and zero schema documentation, the description is far too thin. It omits what validation criteria apply, what the inputs mean, and what a caller receives, leaving the agent unable to invoke it confidently.

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% across five parameters (input, budget, endpoint, candidates, required_fields), some with no type at all. The description mentions none of them, so names like "input," "budget," and "candidates" remain completely undefined.

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+resource ("Structurally validate a machine-service delivery"), which is enough to identify the operation at a high level. However, it offers no differentiation from the sibling service_verify, leaving the agent to guess which of the two validation tools applies.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives among free_diagnostic, service_verify, service_compare, or purchase_decision. The only decision aid is the price, which tells the agent the cost but not when this tool is the right choice.

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