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

Beyond the annotations, it discloses the key behavioral consequence: already-printed copies keep working and resolve to the new address from the next scan, and the change is scoped to the signed-in account. That is genuinely useful context that the destructiveHint/idempotentHint flags do not convey. It doesn't discuss whether the old destination is recoverable or what a failure looks like, which keeps it from a 5.

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 sentences with zero filler; the action is front-loaded, the user-facing consequence follows, and the exclusions close it out. Every sentence 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 two-parameter mutation with full schema coverage and no output schema, the description covers the effect, the persistence behavior of printed copies, and the unsupported code types. Only a note on the failure/response behavior would make it fully 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 100%, so both parameters are already documented in the schema. The description's 'Accepts the code ID or its short link' restates the schema's own wording for the code parameter and adds no format or validation detail beyond it. Baseline 3 applies.

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 and resource — changing the destination web address of a dynamic link QR code in the signed-in account. The scope is sharpened by naming what it cannot touch (static, disabled, photo/PDF/voice note codes), which separates it from create_dynamic_link_code and list_my_codes without opening either schema.

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?

Gives a clear condition for use (dynamic link codes in the signed-in account) and explicit exclusions of the code types this tool rejects. It stops short of naming an alternative tool for those excluded cases, so the agent is left to infer where to go next.

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