Create Suppressions

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

The description adds behavioral context beyond the annotations: the 50-address limit and the read-only blocking behavior. These are not present in the annotations, which only declare readOnlyHint=false, destructiveHint=false, etc. No contradiction exists; the write nature is consistent with readOnlyHint=false.

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?

Two concise sentences: the first states the core action and scope, the second adds a critical restriction. No filler or repetition, and the most important information is front-loaded.

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?

For a simple tool with two well-described parameters, output schema, and annotations, the description is complete. It covers the action, limit, and a key behavioral constraint (read-only blocking). No other contextual gaps are evident.

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 input schema provides 100% coverage with clear descriptions for both stream_id and email_addresses. The tool description does not add parameter-level detail beyond this, so it meets the baseline for high schema coverage but does not enhance it further.

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 uses a specific verb ('Add'), names the resource ('suppression list'), and specifies scope ('up to 50 addresses', 'a stream's'). It clearly distinguishes from siblings like delete_suppressions and list_suppressions by focusing on the create/add action.

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 provides explicit usage context: it is for adding addresses to a suppression list, with a clear limit. It also gives a when-not condition ('BLOCKED in read-only mode'), which is an explicit exclusion. While it doesn't name an alternative tool, the when-not guidance qualifies as explicit usage direction.

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