Batch Add Suppressions

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

With no annotations provided, the description carries the burden of disclosing behavioral traits. It conveys the key effect (suppressed addresses never receive emails) and the automatic nature of hard bounces/spam complaints. However, it does not mention eventual consistency, idempotency, partial failures, or permissions required, leaving some transparency gaps for a mutation tool.

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, front-loaded with the core purpose, and each subsequent sentence adds meaningful context about behavior, usage, and an alternative. There is no redundancy or filler.

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 tool's simplicity (one parameter, no output schema, no annotations), the description covers the essential aspects: what it does, when to use it, and how it relates to alternatives. It lacks explicit information about return values or error behavior, but these are less critical for a straightforward batch add 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 already has 100% coverage: the only parameter 'emails' is described as 'Email addresses to suppress' with format/pattern. The description adds minimal extra semantic value beyond restating 'multiple email addresses,' so a baseline score of 3 is appropriate.

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 opens with 'Add multiple email addresses to the suppression list in Resend in a single call,' clearly specifying the verb, resource, and scope. It distinguishes itself from the sibling 'add-suppression' by explicitly noting the single-address alternative and from batch-remove operations by focusing on adding.

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 states when to use this tool: to manually suppress addresses when needed (e.g., do-not-contact requests), and contrasts this with automatic suppression from hard bounces and spam complaints. It also explicitly directs users to 'add-suppression' for a single address, providing a clear alternative.

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