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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description does not need to restate them. It adds a valuable domain-specific guarantee ('Creates no charge') that goes beyond the annotations and reassures agents about side effects.

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 with no filler. The core behavior is stated first, and the side-effect clarification is a meaningful second sentence that 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 full annotation coverage, the description is nearly complete. It tells the agent what is returned (tiers and prices) and that no charge occurs, though it does not describe the response format, which is minor given the simple scope.

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 tool has zero parameters, so there is no schema-description gap to compensate for. The description's mention of what is being read ('tiers and prices') gives useful context even though there is nothing to document about parameter usage.

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 uses a specific verb ('Read'), names the resource ('fixed website-service tiers and prices'), and clearly distinguishes this from the sibling tools, which handle order status and checkout. Even without the title, an agent would correctly infer the tool's purpose.

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 establishes that this tool is for reading current offers, and the sibling names imply the alternatives are for order status and checkout. However, it does not explicitly say when not to use it or name a specific alternative.

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