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

Annotations include destructiveHint=true, which already signals a mutation. The description adds 'Additive — sends no notification,' providing additional context about side effects, but no further behavioral details are disclosed.

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 three sentences long, front-loaded with the core purpose, and contains no redundant information. Every sentence contributes to understanding.

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?

With 7 parameters, 100% schema coverage, and annotations present, the description adequately covers purpose, a key side effect (no notification), and a usage requirement. It does not explain output or errors, but given the lack of an output schema, this is acceptable.

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 description coverage is 100%, so each parameter is documented. The description adds value by clarifying the requirement to provide at least one identifier (external_id or email), which is not apparent from individual parameter descriptions.

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 it creates a user (notification recipient) in MagicBell, specifying the resource and action. It distinguishes from sibling tools like magicbell_update_user (update) and read 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 mentions 'Provide at least one identifier (external_id or email)' and 'Additive — sends no notification,' which gives guidance on usage. However, it does not explicitly exclude cases or mention alternatives to this tool.

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