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

With no annotations, the description carries the burden of disclosure. It transparently explains the fee structure (setup + monthly plans) and cautions about the distinction between platform fees and merchandise pricing. It doesn't detail return format, but the content is sufficient for a simple read-only lookup with no 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?

The description is concise and well-structured: it opens with the main purpose, then clarifies scope, and ends with a critical usage warning. Every sentence earns its place, with no filler or redundancy.

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 the tool's simplicity (no parameters, no output schema), the description is complete: it covers what the tool returns, clarifies that these are platform fees, and explicitly references the sibling calculate-bulk-price for per-item pricing. This is sufficient for an agent to select and invoke the tool correctly.

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 parameter semantics are not applicable. The baseline of 4 is appropriate; the description avoids adding unnecessary parameter details and instead focuses on the meaning of the returned cost data.

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 clearly states the tool returns Brand Store costs: one-time setup fee and monthly plans (seats, features, price). It explicitly distinguishes this from per-product pricing via calculate-bulk-price, making its purpose unmistakable.

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?

It gives explicit guidance on when to use this tool (for platform/storefront fees) and when not to (for per-item merchandise pricing, which belongs to calculate-bulk-price). It also warns never to present a plan price as a per-item price, preventing misuse.

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