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

Annotations already declare readOnlyHint=true and openWorldHint=true. The description adds important context: it is informational and does not purchase or confirm account-specific access. This clarifies side effects and scope beyond what annotations imply, but does not contradict them. It does not discuss return format or potential variability, but given annotations cover the safety profile, the added context is sufficient.

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 fluff. The primary action and result are front-loaded, followed by a concise limitation and alternative. Every word adds value, and the structure is optimal for quick agent comprehension.

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 is simple: one required enum parameter, no output schema, and annotations cover safety. The description lists the return fields, clarifies its informational nature, and provides a routing alternative. It does not describe error cases or the exact JSON shape, but that is a minor gap given the simplicity. Overall it is complete enough for correct invocation.

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 100% for the single parameter 'model', which already provides a clear description. The tool description does not add further details about the parameter or its enum values, so it does not enhance what the schema already documents. This aligns with the baseline of 3.

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 ('Returns') and a clear resource ('public access terms for an engine'), and enumerates the exact fields returned: product, annual price, billing period, annual allowance, and customer checkout URL. It also explicitly contrasts itself with get_account_access, distinguishing it from the most similar sibling.

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 tells the agent when to use this tool (for informational public access terms) and when not to (for authenticated account access), pointing to the alternative tool get_account_access. This provides clear routing guidance with no ambiguity.

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