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

No annotations, so the description carries the full burden, and it does substantial work: it discloses the auth requirement (Bearer fq_...), the plan requirement, and an important lifecycle behavior ('redirect keeps working even if the plan lapses'). What it omits is what happens on failure (e.g., missing key, expired plan) and whether creation is reversible/deletable. Still, for an unannotated mutation tool this is above-average behavioral disclosure.

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 short sentences, each earning its place: what it does, what it requires, and a non-obvious behavioral guarantee. Front-loaded with the core action and free of filler.

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 2-parameter creation tool with no output schema, the description covers purpose, auth, plan requirements, and redirect persistence. The main gap is the undocumented 'label' parameter and no mention of what is returned or what happens on failure, but the core calling context is complete.

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 coverage is 50%: 'target' is documented as an HTTPS destination URL, but 'label' has no description anywhere. The tool description mentions neither parameter by name nor adds semantics. With half the parameters undocumented, the description does not compensate, so this lands at the baseline.

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?

States a specific verb+resource ('Create an editable (dynamic) QR code') and explains the redirect mechanism via the fixedqr.com/r/<id> URL pattern. This clearly distinguishes it from generate_qr (presumably static) and update_dynamic_code, which implies this is the creation counterpart to a separate update tool.

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 states prerequisites (API key, active plan), which implicitly tells the agent when the tool is usable. However, it never states when to prefer this over generate_qr or update_dynamic_code, nor does it give exclusions. The usage context is implied by the prerequisites rather than made explicit.

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