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

Annotations cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false). The description adds substantive behavioral context beyond that: MESSAGE campaigns have no Contacts and their recipients live on the campaign, and it names which fields carry the data (messageStats with Open Profile split, linkedinConnectionIds, get_message_targets). This is genuinely useful disclosure, though it stops short of pagination or failure semantics.

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 purpose, then branches into type-specific detail and sibling routing. Every sentence earns its place, though the MESSAGE-campaign paragraph is dense and could be slightly tighter.

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?

No output schema exists, so the description appropriately explains what the return contains (statistics, prospect count, messageStats, linkedinConnectionIds) and how to reach the underlying records. It compensates for the missing output schema without over-explaining, though edge cases like campaign-not-found behavior are absent.

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?

Only one parameter, campaignId, and schema coverage is 100% with an inline description. The description adds no syntax or format detail beyond what the schema provides, so the baseline 3 for high-coverage schemas 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?

States a specific verb (get) and resource (full details of a specific campaign), and explicitly names the outputs returned (statistics, prospect count). It also distinguishes campaign types (MESSAGE vs Contact-based) and points to the correct siblings when the caller's need diverges.

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?

Explicitly routes the caller: use get_contacts(campaignId) to list actual prospect records, add_lead_to_campaign/create_lead to add prospects, and get_message_targets to list message recipients. This is exactly the when-to-use-this-vs-alternatives guidance the dimension expects.

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