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

Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the safety profile is covered. The description goes beyond them by disclosing the credit spend, the approval-gating rule, and the irreversible side effect of locking the definition. It does not describe failure modes or partial-spend behavior, which keeps it at a 4.

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?

Four short, front-loaded sentences with no filler. The primary effect (launch and spend credits) leads, followed by the approval precondition and the locking side effect, each sentence carrying a distinct constraint.

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?

An output schema exists, so return values need not be described. The description covers the prerequisite sibling call, the cost constraint, and the state mutation, which is enough for correct invocation. It leaves failure/rollback behavior and the meaning of the revision parameter unaddressed.

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 0%, so the description must carry parameter meaning. It gives real semantics for maximumCharge (it is the exact approved amount, with a re-approval trigger if it changes), but says nothing about definitionRevision or testId, leaving two of three required parameters to inference from the schema.

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 (launch) and resource (the previewed revision) plus the material consequence (spends credits, locks the definition). It is clearly distinguishable from the sibling preview_test_launch, which appears as the prerequisite rather than a duplicate.

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?

Establishes the workflow prerequisite: costs must first be approved via preview_test_launch, and maximumCharge must equal that approved amount. It also notes that cost changes invalidate the approval and require a new one. It does not state outright when not to use this tool, so it stops short of a 5.

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