mailchimp_members_add_or_update

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

No annotations are provided, so the description must disclose behavior. It only restates the tool's purpose and adds the term 'upsert,' which adds no new behavioral detail. It does not explain how existing members are matched, whether updates are partial, or how status_if_new applies to new vs. existing members.

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, direct sentence with no redundant words. It is front-loaded with the core action and is appropriately brief for the tool's purpose.

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?

The tool has 7 parameters including nested objects, yet the description provides no information about return values, error handling, or how the upsert is determined. It also doesn't clarify whether updates are partial or which fields apply only to new members, leaving significant gaps for a complex operation.

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 full descriptions for all 7 parameters (100% coverage), so the description adds no parameter-level meaning beyond what the schema already offers. Baseline score 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?

The description clearly states the tool's action: adding or updating a member (upsert). This distinguishes it from sibling tools like mailchimp_members_add and mailchimp_members_update by covering both operations in one call.

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 (upsert scenario) but does not explicitly contrast it with mailchimp_members_add or mailchimp_members_update. It lacks exclusions or alternative recommendations, leaving the agent to infer the decision.

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