Update a specific user's preference by classifier and name, setting its value through the VCF Automation API.
Update a preference for a specific user. PUT /cloudapi/1.0.0/users/{userUrn}/preferences/{classifier}
| Name | Required | Description | Default |
|---|---|---|---|
| body | Yes | Definition of Preference. | |
| userUrn | Yes | (path) | |
| classifier | Yes | (path) |
Changes observed during successful MCP inspections.
v0.2.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so safety is covered externally. The description adds only the raw REST path and omits meaningful behavior: that 'classifier' is immutable and must match between path and body, and what happens if the preference does not exist (404 vs create).
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 short lines with no filler and the purpose statement front-loaded. The raw HTTP path is marginally useful as routing context but borders on noise since it restates the parameter names.
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 mutation tool with no output schema, full schema coverage and rich annotations, the minimal description is nearly adequate. However, it leaves the path/body classifier redundancy and the immutability constraint unexplained, which are the details an agent is most likely to get wrong.
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 including the nested body fields are documented in the schema, making 3 the baseline. The description adds nothing beyond the path echo, and notably fails to explain the duplication of 'classifier' as both a path parameter and a required body field, which is the one ambiguity an agent would need help with.
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 and resource ('Update a preference for a specific user') and reinforces it with the REST path, so the operation is unambiguous. It does not, however, distinguish itself from closely-named siblings like provider_update_preference, identity_update_user_preferences, or provider_get_user_preference, so an agent must guess which one to pick.
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?
There is no guidance on when to use this tool versus the near-identical siblings (provider_update_preference, identity_update_user_preferences), no prerequisites, and no note that the preference must already exist. The agent gets a verb and a path, nothing about selection.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.