list_suppressionsList suppressed recipient addresses.
| Name | Required | Description | Default |
|---|---|---|---|
| No | Optional filter by email | ||
| limit | No | Page size (1–100) | |
| cursor | No | Opaque cursor for the next page |
| Name | Required | Description | Default |
|---|---|---|---|
| data | Yes | Suppressed addresses | |
| has_more | No | True when another page follows | |
| next_cursor | No | Pass as cursor for the next page; null on the last page |
Changes observed during successful MCP inspections.
Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "data": {
+ "description": "Suppressed addresses",
+ "items": {
+ "properties": {
+ "created_at": {
+ "description": "ISO 8601",
+ "type": "string"
+ },
+ "email": {
+ "type": "string"
+ },
+ "id": {
+ "description": "Suppression id",
+ "type": "string"
+ },
+ "reason": {
+ "type": [
+ "string",
+ "null"
+ ]
+ },
+ "source": {
+ "type": "string"
+ },
+ "updated_at": {
+ "description": "ISO 8601",
+ "type": "string"
+ }
+ },
+ "required": [
+ "id",
+ "email"
+ ],
+ "type": "object"
+ },
+ "type": "array"
+ },
+ "has_more": {
+ "description": "True when another page follows",
+ "type": "boolean"
+ },
+ "next_cursor": {
+ "description": "Pass as cursor for the next page; null on the last page",
+ "type": [
+ "string",
+ "null"
+ ]
+ }
+ },
+ "required": [
+ "data"
+ ],
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered without description help. The description adds nothing beyond this — no note on pagination behavior, filtering semantics, or result ordering — so it does no work the structured fields don't already do.
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?
A single front-loaded sentence with zero filler or redundancy. It is efficient, though the brevity edges toward under-specification for a paginated list operation.
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?
The output schema covers return values and the annotations cover safety, so the remaining burden is light. However, the description omits pagination and filter behavior implied by the cursor/limit/email parameters, leaving it merely adequate for a low-complexity read tool.
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 all three parameters (email, limit, cursor) are fully documented in the schema. The description adds no parameter meaning beyond that, making the baseline 3 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?
States a specific verb ('List') and resource ('suppressed recipient addresses'), which is clear enough to distinguish it from add_suppression and remove_suppression by name alone. It stops short of an explicit sibling comparison, but the read vs. write distinction is unambiguous.
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, no mention of prerequisites, and no exclusions. The agent must infer that this is the read counterpart to add_suppression/remove_suppression and that pagination via cursor is expected.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.