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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds the valuable 'Creates no charge' billing guarantee and 'current' freshness qualifier, going slightly beyond the structured fields. No contradictions with annotations.

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 sentences, front-loaded with the action, followed by the no-charge clarification. There is zero waste and every phrase earns its place.

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 zero-parameter read-only tool with no output schema, the description is sufficient: it names the exact data returned and assures no side effects. It could have briefly mentioned the sibling alternative for order status, but that omission does not impair successful 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 input schema has zero parameters, so the description carries no parameter burden. Per calibration, this is a solid baseline score with no gaps to penalize.

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 ('Read') and a specific resource ('current fixed FAIE Signal Brief and Proof Sprint offers'), making the tool's purpose unmistakable. The named offer types distinctively set it apart from sibling tools like get_faie_order_status and prepare_faie_checkout.

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 clearly implies this tool is for retrieving current offers, but it never explicitly contrasts it with the sibling tools (e.g., 'use get_faie_order_status for order status'). The safety note 'Creates no charge' hints at when it's appropriate, but no direct usage guidance or exclusions are provided.

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