list_usersList account users to find valid emails for the X-AuditUser header required on write operations.
List users on the account. Use this to find valid emails for the X-AuditUser header required on write operations. Read-only.
| Name | Required | Description | Default |
|---|---|---|---|
| account | No | Which configured FastBound account to use for this one call — an alias or account number (see list_accounts). Omit to use the active account. |
Changes observed during successful MCP inspections.
v0.2.0Input schema / additionalPropertiesAdded value: +falseInput schema / properties / accountAdded value: +{
+ "description": "Which configured FastBound account to use for this one call — an alias or account number (see list_accounts). Omit to use the active account.",
+ "type": "string"
+}v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The readOnlyHint/openWorldHint annotations already cover safety; the description adds account scoping and the write-header use case, but does not reveal behavior such as return shape or pagination. There is no contradiction with annotations.
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 sentences with front-loaded purpose and a clear use case. The final 'Read-only.' is redundant given readOnlyHint=true, so it is not perfectly earned, but the overall description is compact and scannable.
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 read-only list with one optional parameter, the description is largely complete: it identifies the resource, the account scope, and why an agent would call it. It does not describe the output shape, but absent an output schema this is a minor gap rather than a blocking one.
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 only parameter, 'account', has 100% schema description coverage. The main description adds no additional parameter semantics, so the baseline of 3 applies.
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 and resource ('List users on the account') and states the practical purpose (finding valid emails for the X-AuditUser header), so an agent can distinguish it from the many account/contact/search siblings without opening the schema.
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?
It gives explicit guidance for when to use the tool: 'Use this to find valid emails for the X-AuditUser header required on write operations.' It does not state when-not-to-use or name alternatives, but none of the siblings is a competing user-list tool, so this is clear enough.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.