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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds that a real prospect is merged, meaning the preview reflects actual prospect data rather than a template, and that nothing is sent pre-launch. It does not clarify whether the merge has any persisted side effect, which is the one point where 'merge' phrasing could mislead.

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?

A single sentence with no filler, front-loaded on the action and ending on the payoff. Nothing is padded and nothing needs trimming.

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 tool with no output schema, the description does minimally convey what the agent gets back (readable messages). It stops short of describing the shape of the preview (per-prospect message list, sequence steps) or the fallback behavior for the optional prospect, leaving a modest gap given the absence of an output schema.

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 50%: prospect_id carries its own fallback description ('otherwise uses an enrolled or recent prospect'), while campaign_id is undocumented everywhere. The description contributes no parameter-level information, so it neither compensates for the gap nor adds meaning beyond 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 concrete action (merge a real prospect into the campaign sequence) plus the user-facing outcome (read the messages before launch), which lets an agent separate it from launch_campaign or get_campaign. The verb 'merge' is domain jargon and slightly ambiguous about what is actually produced, but the intent is clear.

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?

The phrase 'before launch' implies the usage context (pre-send review of a campaign), so an agent can infer when it applies. However, no alternative tool is named and there is no explicit statement of when not to use it (e.g., versus get_campaign or approve_review).

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