Add contact to campaign

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

Annotations already declare readOnlyHint=false, openWorldHint=true, and idempotentHint=true, so the agent knows this is a mutating, potentially side-effecting, idempotent operation. The description adds 'starting it for them', which hints that the campaign is initiated for the contact, but it does not explain possible side effects (e.g., triggered emails) or the meaning of idempotency. It provides minimal extra context beyond the annotations and does not contradict them.

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 a single sentence of ten words that states the core action and its result without unnecessary words. It is front-loaded with the verb and object, and the clarifying phrase 'starting it for them' adds value without bloat.

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 simple two-string-parameter tool with no output schema, the description is mostly complete. It tells the agent what the tool does, and annotations cover safety and idempotency. However, it does not mention what happens if the contact is already in the campaign, precondition requirements, or error cases. Given the simplicity, the gaps are minor but non-negligible.

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 schema provides no descriptions for contactId and campaignId, and the description does not compensate. While the parameter names are self-explanatory (IDs of contact and campaign), the description does not clarify their format, required scope, or any relationship to other data. With 0% schema description coverage, the tool description should carry more interpretive weight, but it is silent on parameters.

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 uses a specific verb 'enroll' with a clear resource 'a contact into a campaign', and adds 'starting it for them' to clarify the effect. This distinguishes it from sibling tools like ghl_remove_contact_from_campaign and ghl_add_contact_to_workflow, so an agent can understand its purpose without inspecting other tools.

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 description implies when to use the tool (when you want to enroll a contact in a campaign) but provides no explicit guidance about alternatives or exclusions. It does not mention that ghl_remove_contact_from_campaign is the inverse, nor when to prefer this over ghl_add_contact_to_workflow. Usage context is left to inference.

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