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

With no output schema, the description carries the return contract: originAllowed, runId, and the exact verify command. It also discloses non-obvious traits the annotations don't cover: each call starts a new run (reinforcing non-idempotency), only the latest runId is valid, sign-in and later checks block until the sandbox guest exists, and the key only accepts localhost, not 127.0.0.1.

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 dense and front-loads the trigger condition and the localhost constraint, with the example at the end. A few clauses are compressed to the point of terseness ("Store key:", the runId sentence), which costs a point against a clean 5.

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 non-destructive-but-stateful connect tool with no output schema, the description explains what the call returns, how to use the result (run the verify command as returned while the site runs), how to recover from originAllowed=false, and the run lifecycle. Nothing an agent needs to invoke it correctly appears missing.

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 the baseline is 3, but the description earns credit by adding constraints the schema omits: the origin must use http://localhost:<port> (not 127.0.0.1), and a worked example shows the storefrontKey/origin shape. It does not add much about the optional `path` parameter beyond what the schema says.

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 opening fragment "Store key:" is terse, but the sentence that follows states the specific action: connecting a site served from a persistent process and obtaining its verify command. It is distinguishable from siblings like storefront_verify_result and checkout_verify because it produces the verify command rather than reporting a result.

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?

It gives an explicit precondition ("call when the site is served from a process that keeps running (background, fixed port) and menu items show at that origin") and names the fallback route: "If originAllowed is false, read kit_docs_get topic onboarding." Use of the returned verify command vs. stubbing sign-in is also spelled out.

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