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

Annotations only indicate non-read-only and non-destructive hints, which don't fully disclose the tool's behavior. The description adds key non-obvious traits: it creates a 'real' quote, is 'agent-only', and explicitly does not charge. This goes beyond the annotations, providing valuable behavioral context that helps an agent avoid assuming payment occurs.

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 zero fluff. The first sentence states the primary action and target, the second clarifies a crucial non-behavior. Every word adds value, and it is front-loaded with the core purpose.

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?

The tool has no output schema, so the description could have explained what the tool returns. It does not, but given the simplicity (single parameter, clear action), the missing return info is a minor gap. It does provide the essential context: it creates a quote, does not charge, and is agent-only. For a quote-creation tool, this is mostly sufficient.

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?

The schema description coverage is 0%, so the description must compensate. Although the description does not explicitly mention 'offerId', it refers to 'an active NAIF Market Maker offer', implying that the sole parameter is the ID of that offer. This provides contextual meaning (active, agent-only) beyond the raw string type, helping the agent understand what value to supply.

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 (Create), a specific resource (real agent-only USDC quote), and the context (an active NAIF Market Maker offer). This clearly distinguishes the tool from its siblings, none of which mention quote creation or offer acceptance. The title slightly says 'Accept' but the description clarifies the actual action, resolving ambiguity.

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 explicitly states what the tool does NOT do: it does not charge or submit payment, and checkout is a separate step. This gives clear context for when to use it (to create a quote) vs. not to use it (for payment). However, it doesn't mention any alternative tool or provides a 'when not' that lists a sibling, but given the distinct purpose, it's adequate.

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