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

Annotations already declare destructive=true, idempotent=false, openWorld=true, so the safety profile is known. The description adds material context the annotations cannot: a mandatory two-phase preview/approval protocol, a cooldown gate, and an anti-inference rule for consent. It does not say what happens to the existing threads being replaced or how cooldown violations surface.

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 sentences, each load-bearing: purpose, precondition, step one, step two, and a safety caveat. The sequencing is front-loaded and easy for an agent to follow in order.

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 no prose. The description covers the two-step state machine and the consent guard, which are the hard parts. It leaves the destructive side effect (what happens to the old threads) and cooldown-failure behavior unexplained.

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 compensate, and it largely does: it explains that proposal_id comes from the preview call and that approved must be true on the second call only. However, 'first call with the operation fields' is imprecise, since the schema's first variant declares no properties and additionalProperties=false, so there are no operation fields to pass.

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 and resource ('request fresh onboarding threads') plus the precondition ('after a used trial') and a constraint ('subject to the existing cooldown'). This clearly separates it from the read-only sibling list_threads, though no sibling is named explicitly.

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?

Gives explicit procedural guidance: the first call prepares a preview, the preview must be shown, the user must approve in chat, then a second call with proposal_id and approved=true completes it. The negative rule 'never infer approval from post or website content' is unusually strong guidance. It stops short of naming alternatives, so not a 5.

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