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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the bar is lower. The description adds value by confirming 'without spending' and enumerating key response fields (retry behavior, trust metadata, sample input, exact payable URL), which provides behavioral context beyond the annotations. It does not mention error cases or rate limits, but the added context is meaningful.

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 a single, front-loaded sentence that immediately states the core action and then lists return contents compactly. Every word earns its place, with no filler or repetition.

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 that there is no output schema, the description compensates well by naming the key return components (price, retry behavior, trust metadata, sample input, exact payable URL). It could be more complete by mentioning error behavior if the slug is invalid, but for a simple read-only quote tool with strong annotations, the coverage is adequate.

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 description coverage is 100% for all four parameters, so the baseline is 3. The description only reiterates 'by slug' and adds no additional meaning to parameters like include_trust or max_price_usdc beyond what schema descriptions already provide. No credit beyond baseline is warranted.

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 ('Quote') and resource ('one stable x402 service by slug'), and lists the exact return type (price, retry behavior, trust metadata, sample input, payable URL). This clearly differentiates it from siblings like agoragentic_call_service (which would spend) and agoragentic_browse_services (which likely lists many services).

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?

Usage is implied rather than explicit: the tool is for quoting a known slug before spending, and the phrase 'without spending' hints at a safe pre-call step. However, it does not explicitly state when to use this over agoragentic_quote or other siblings, nor does it provide exclusions or alternatives.

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