cm_set_client_primary_contact

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

Annotations provide idempotentHint, which the description does not contradict. However, the description adds no behavioral context beyond what annotations already offer, such as potential side effects (overwriting existing contact) or required permissions. With annotations present, this is adequate but minimal.

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 focused sentence that efficiently conveys the tool's core purpose. It is concise and front-loaded, with no wasted words.

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 the simple two-parameter schema and idempotent annotation, the description captures the essential action. However, it omits details about prerequisites (person must exist), effects on previous primary contact, and any return value, which would be useful for an agent in a complex tool ecosystem.

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 has 100% coverage with descriptions for both parameters (clientId and email). The tool description does not add any parameter-specific information, so it meets the baseline expectation but does not exceed it.

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?

Description clearly states the action ('Set'), the resource ('client's primary contact'), and the target ('existing person'). It distinguishes from sibling tools like cm_get_client_primary_contact (read) and cm_set_account_primary_contact (different resource).

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 on when to use this tool versus alternatives such as cm_set_account_primary_contact or prerequisites like the person must already exist. The single sentence implies but does not specify usage context.

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