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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering safety. The description adds valuable context: 'without spending' reinforces the read-only nature, and listing the return fields (price, retry behavior, trust metadata, sample input, exact payable URL) gives insight into what the response contains. No contradiction detected.

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?

The description is two sentences with no wasted words. It front-loads the primary action and then lists the key return elements. Every segment earns its place, making it easy to parse quickly.

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?

Given the tool's simplicity (one required parameter, no output schema), the description is complete: it states the purpose, lists all major return items, and clarifies the non-spending aspect. The parameter descriptions in the schema cover the optional flags and safety bound, so nothing critical 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?

Schema coverage is 100%, and each parameter has a clear description. The main tool description does not add extra semantic detail about parameters beyond what the schema already provides. It does indirectly reference include_trust and include_schemas via the return list, but not explicitly. This is adequate but not exceptional, warranting the baseline score.

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 clearly states the tool's purpose: 'Quote one stable x402 service by slug.' It specifies the resource (x402 service), the action (quote), and the scope (by slug). It also lists the return contents, distinguishing it from sibling tools like call_service (execution) and browse_services (listing).

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 implies usage context: you need a known slug and want a quote before spending. The phrase 'without spending' signals this is a pre-invocation check. However, it does not explicitly mention alternatives or exclusions, such as using agoragentic_quote for a different quoting scenario, so it stops short of full guidance.

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