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

With no annotations provided, the description carries the full burden. It discloses the return format (a pre-formatted markdown table), lists the exact fields, instructs the agent to display the table verbatim, and notes authentication requirements. This goes beyond the schema and helps the agent handle the response correctly.

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, with each sentence serving a purpose: purpose, return format, handling instruction, and authentication. The field list is long but necessary to convey the table structure, so it remains appropriately sized.

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 simple read-only tool with one parameter and no output schema, the description provides the essential return details and an explicit handling instruction. It does not mention error cases (e.g., QR code not found), but this is a minor gap given the tool's simplicity.

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 already documents the single parameter (qr_code_id) with a clear description ('Internal UUID of the QR code'), and the description does not add additional detail about the parameter itself. Therefore it meets the baseline for full schema coverage.

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 begins with a specific verb and resource: 'Get the total lifetime scan count for a QR code.' It clearly distinguishes this tool from siblings like get_qr_code or list_qr_codes by focusing solely on the lifetime scan metric.

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 purpose is so specific that the intended use is clear: to obtain a QR code's lifetime scan count. It does not explicitly name alternatives or exclusions, but the sibling tool names and the description's focus provide enough context to avoid confusion.

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