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

With no annotations provided, the description carries the full burden of disclosing behavior. It explicitly mentions that the operation requires authentication, that it does not touch the printed image, and that the success response is a pre-formatted markdown table that must be displayed as-is. This covers key behavioral aspects, though it could elaborate on reversibility or 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 front-loaded with the primary purpose. Each sentence contributes: the main action, the 'print once' benefit, parameter selection, response format instruction, and authentication requirement. No unnecessary fluff, and the structure flows logically.

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?

The tool has no output schema, so the description's mention of the markdown table response compensates for that. The description covers the core behavior, parameter selection, and authentication. A minor gap is that it does not explicitly state that at least one of qr_code_id or short_code is required, though this is implied by 'Accepts either.'

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 has 100% coverage, so the baseline is 3. The description adds value by explaining that either qr_code_id or short_code can be used, a relationship not captured in the schema. It also clarifies that short_code comes from the redirect URL, adding context beyond the schema's descriptions.

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's purpose: changing the destination URL of an existing QR code without affecting the printed image. This distinguishes it from sibling tools like create_qr_code and delete_qr_code, and the phrase 'Change the destination URL' is a specific verb+resource combination.

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 implies when to use this tool (when you need to redirect a QR code after printing) and explains how to specify the target (via qr_code_id or short_code). It does not explicitly state when not to use it or mention alternative tools, but the context is clear and it includes the prerequisite of authentication.

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