hub_send_campaign

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

With no annotations, the description must fully disclose behavior. It only says 'send' and 'routes' without explaining how routing decisions are made, what 'best' means, whether it can fail, or if there are side effects like audience targeting or cost implications. It also doesn't mention prerequisites such as authenticated platform connections. The lack of detail on routing logic is a significant gap for an agent deciding to call this tool.

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 concise (two sentences) and avoids fluff. However, it could add a bit more detail without becoming verbose, such as mentioning that preferred_platform can override automatic routing or that segment_name defines the audience. It's under-specified rather than efficiently informative.

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?

Given there is no output schema, no annotations, and 0% schema coverage, the description is far from complete. It does not explain which parameters are required (campaign_name is required but no mention), how the routing decision works, what happens if the preferred platform is invalid, or what the response looks like. An agent has almost no context to call this tool correctly.

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?

The description provides zero information about the six parameters. Since schema description coverage is 0%, agents must infer meaning solely from param names (campaign_name, channel, subject, content_html, segment_name, preferred_platform). The description doesn't clarify the role of preferred_platform (which directly relates to 'best available platform') or how channel restricts routing. This is a major omission.

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 clearly states the action ('Send a marketing campaign') and the subject (marketing campaigns). It lists potential platforms (Mailchimp, HubSpot, WebEngage, Braze, CleverTap) which distinguishes it from transactional sends like hub_send_transactional. However, 'best available platform' is ambiguous and not fully defined, and it doesn't contrast with other campaign-related siblings like schedule_content or launch_campaign_ad.

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?

No guidance is provided on when to use this tool versus alternatives. It does not mention conditions for using hub_send_transactional (for transactional messages) or schedule_content (for scheduled posts). There is no explicit 'when not to use' or preferred scenarios. The only hint is that it's for marketing campaigns, but that's implied, not stated as a selection criterion.

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