mhlb_init_checkout

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

Annotations indicate readOnlyHint=false and openWorldHint=true. The description adds critical behavioral detail: it is a non-charging read step, but the confirm flag implies potential side effects beyond pure read (e.g., creating a checkout session). It also discloses that the request shape is unverified and advises inspecting the dry-run preview. This adds transparency beyond what annotations provide, though it could have been more explicit about whether confirm triggers any state mutation.

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 compact: three sentences that front-load the main purpose and return values, followed by a crucial unverified warning. It avoids redundancy and keeps the critical caveat near the end without diluting the core message. Minor excess: 'as mhlb_init_checkout reports it' for checkoutType is a bit circular, but overall efficient.

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 checkout-init tool with no output schema, the description adequately covers purpose, usage sequence, and safety warnings. It references related tools for parameter sources and clarifies the confirm behavior. The main gap is potential side effects of confirm=true (does it create a session or just return preview?), but that is partially covered by the unverified warning. Overall complete for confident invocation.

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 description coverage is 100%, giving a baseline of 3. The description adds cross-references (e.g., orderIds 'from mhlb_get_cart', checkoutType 'as mhlb_init_checkout reports it', schoolDonations 'as returned by mhlb_init_checkout') that tie parameters to their source or expected format. It also clarifies confirm's role. These enrich the schema, justifying a 4.

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 states a specific verb ('Start checkout') and resource ('the cart'), and details what it returns (order summary, totals, taxes, applied credits, payment methods). It also distinguishes itself from mhlb_checkout by labeling itself as the read step before the charging action, making it clearly differentiated from siblings.

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?

Explicitly states when to use it ('the read step before mhlb_checkout') and clarifies what it does not do ('does NOT charge anything'). It also instructs on the confirm flag: without true, returns a preview, with true proceeds. This gives clear operational guidance and anticipates the checkout sequence.

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