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

Annotations already flag destructiveHint=true, but the description adds substantial context beyond them: what is destroyed (lists, queued emails), what is preserved as contact history (enrolments, messages), that recipients cannot be re-emailed from scratch, that late replies still reach the Inbox, and that there is no undo. It also discloses the approval_token gate and the exact shape of the approval_required response.

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 its consequences, and the approval mechanism is stated before the closing scope note. Slightly redundant phrasing ('as the dashboard does' / 'Every dashboard guardrail still applies') costs a little, but nearly every sentence carries information.

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 destructive mutation with no output schema, the description covers the full picture: irreversibility, data retention, the approval handshake, and the error payload an agent must parse. Nothing needed to call it correctly is 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 adds real meaning beyond the schema by explaining the approval_token lifecycle: the first call without it returns {error, approval_token, summary}, and the second call supplies the token after user confirmation. That is operational semantics the schema alone does not convey.

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 ('Delete a campaign') and immediately distinguishes the operation from sibling lifecycle tools by describing its effects: it leaves every list and queued emails stop. An agent can tell this apart from pause_campaign/resume_campaign/duplicate_campaign without opening a schema.

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 clear context for when this is appropriate ('exactly what a user clicking the dashboard could do, no more') and explains the guarded two-step confirmation flow. It stops short of explicitly routing the agent to an alternative such as pause_campaign for a reversible stop, so the when-not guidance is implied rather than stated.

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