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

The description goes beyond the idempotentHint: false annotation by explaining that it reads a local file, proves authorization, and triggers a redirect. It doesn't cover error handling or rate limits, but for a simple verification step, it's informative.

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 a few sentences, front-loaded with the primary action, and includes only necessary details. It could be slightly more compact but is clear and well-structured.

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?

Given a single parameter, annotations, and the presence of an output schema, the description covers the what, when, how, and outcome. It doesn't discuss error scenarios, but for a simple tool this is sufficient.

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% and the schema already describes the code pattern. The description adds minimal extra context ('code in the user's browser'), but the baseline of 3 is appropriate since schema does the heavy lifting.

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 starts with 'Confirm a pairing code' which is a specific verb and resource. It provides the exact URL pattern and distinguishes this verification from sibling tools like verify_sending_domain or verify_site by tying it to the claim workflow.

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 explicitly states 'Use ONLY in the agent session that originally published the site' and explains the prerequisite of .shiply.json in the current directory. It also notes the outcome (auto-redirect to /welcome). No explicit alternatives are given, but the context is narrow enough that this is clear.

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