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

With no annotations, the description carries the full behavioral burden. It usefully discloses the authentication and plan requirement, which an agent must know before calling, but says nothing about ordering, default result set, rate limits, or what happens on an empty account.

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?

Three tight sentences with no filler: purpose first, capabilities second, prerequisite third. Nothing is redundant and the most important information is front-loaded.

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 listing tool with three optional parameters, full schema coverage, and no output schema, the description covers purpose, filtering, pagination, and access requirements. Only minor gaps remain around result ordering and the shape of the returned list.

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?

Schema description coverage is 100%, so page, limit, and type are already fully documented with ranges, defaults, and an enum. The description only restates that pagination and type filtering exist, adding no syntax or format detail beyond the schema.

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 names a specific verb and resource ('List QR codes') and scopes it to 'the authenticated user's account,' so the agent knows exactly what is returned. It stops short of explicitly contrasting itself with siblings like generate_qr_code or get_analytics, though the distinction is fairly obvious from the read-only listing framing.

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?

Usage is implied rather than stated: the agent can infer this is the retrieval path for QR codes and that pagination/type filtering are available. It states a prerequisite (authenticated API key on the Developer plan), which is genuinely useful, but offers no explicit when-to-use-this-vs-alternatives guidance.

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