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

Annotations already declare read-only, idempotent, non-destructive behavior, so the description need not restate safety. It adds useful behavioral context about the campaign being 'as it is saved,' product block item behavior, fallback pricing for anonymous readers, and `productsLeftOut` entries that will not display.

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?

The description is dense but front-loads the core purpose and then adds relevant return-shape details. Some sentences, especially the products block explanation, are compact and parenthetical, but there is little obvious filler.

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?

Output schema exists, so full return-value documentation is not required. The description still covers the important compatibility detail that the body shape matches `updateCampaign`'s `blocks` parameter and explains key products-block behavior, making it largely complete for an agent.

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 both parameters are already documented. The description adds that `broadcastId` comes from `readCampaigns`, but does not expand on `workspaceId` beyond what the schema says, so it provides only marginal added meaning.

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?

The description states a specific verb and resource: it reads one saved campaign and enumerates the fields returned. It also distinguishes itself from `readCampaigns` by noting that tool lists broadcast IDs, so an agent can choose the singular tool for one campaign without opening schemas.

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?

It gives a clear prerequisite (`broadcastId`, obtainable from `readCampaigns`) and a workspace constraint for subscribed email contacts. It does not explicitly say when to avoid this tool versus `updateCampaign` or other campaign-related siblings, but the usage context is clear.

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