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 structurally. The description usefully adds that wallet dollars are actually spent, which is not in the annotations, but omits that the spend is irreversible, that the full estimated budget may be charged, and what happens on failure.

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?

One front-loaded sentence with no filler; the financial consequence is stated immediately. It is tight but arguably too terse given the operation's gravity.

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, money-spending action with no output schema, the description covers the core action and its cost side effect. It still leaves the agent without guidance on pre-flight checks (cost estimate) and post-launch state, which matters for an irreversible operation.

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?

confirmed is fully documented in the schema, including the approval precondition, while campaign_id has no schema description. The description's reference to a 'draft mail campaign' and recipient spending adds only mild meaning to campaign_id and does not compensate for the 50% coverage gap.

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?

Names a specific verb (launches) and resource (draft mail campaign), plus the monetary consequence. This clearly separates it from creating (post_mail_campaigns), editing (patch), and pause/resume siblings, though it doesn't explicitly call out those alternatives.

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?

Implies the workflow (a draft is launched), but never states when to use this versus fetching a cost estimate first, nor what conditions should block a launch. The precondition is only hinted at through the confirmed parameter's schema text.

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