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

Annotations already flag destructiveHint=true and idempotentHint=true, but the description goes well beyond them by enumerating exactly what is destroyed (unsent follow-ups are canceled and do not return on re-attach), what is preserved (already-sent emails untouched), and what happens to a live campaign (rescheduled onto remaining senders). This is precisely the operational detail an agent cannot infer from the hints.

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?

Front-loaded with the core action and consequence; the destructive side effects follow in a tight clause chain, and the idempotency note closes it out. No filler sentences.

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 two-parameter destructive mutation with no output schema, the description covers side effects, reversibility (do not come back on re-attach), and idempotency, which is everything an agent needs to call it safely.

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% and both parameters (campaign id, senderEmailId) carry source pointers in the schema itself. The description adds no additional parameter-level meaning, so the baseline 3 applies.

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?

Specific verb (detaches) plus resource (sender email from a campaign) with a clear outcome clause ('so the campaign stops sending through that mailbox'). The counterpart sibling attach_campaign_sender_emails is implied by 're-attach', making the direction of the operation unambiguous.

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?

Usage context is implied by describing the effect of detaching, and the idempotent no-op clause tells the agent it is safe to call blindly. However, it never explicitly states when to choose this over the sibling attach_campaign_sender_emails or what an agent should do instead when it wants to swap mailboxes.

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