add_suppression

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions that the email is added to a suppression list and blocks future sends, but it does not mention what happens if the email already exists, whether the operation is reversible, or any required permissions.

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 extremely concise with two sentences that directly convey the core purpose and effect. Every word earns its place; no filler or redundancy.

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 no output schema, no annotations, and 4 parameters with low schema coverage, the description is insufficiently complete. It lacks information about success/failure responses, idempotency, error conditions, or rate limits. A write operation like this needs more context.

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 only 25% (apiKey described). The tool description adds no parameter details beyond the schema. It does not explain the 'notes' or 'reason' parameters, nor does it clarify the email format or validation rules. The baseline of 3 is not met because coverage is low and description does not compensate.

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 ('Add an email') and the resource ('suppression list') with a concrete consequence ('Future sends to this address will be blocked'). It differentiates from sibling tools like remove_suppression and list_suppressions.

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 usage for blocking a specific email from future sends, but it does not provide explicit guidance on when to use this tool versus alternatives (e.g., adding to audience lists) or any prerequisites or exclusions.

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