Create new user aliases for existing users or alias-only profiles, attaching alias names and labels to Braze profiles for identification.
Create new user aliases for existing users or create alias-only profiles.
| Name | Required | Description | Default |
|---|---|---|---|
| apiKey | No | Braze REST API key (optional if set via env/header) | |
| restEndpoint | No | Braze REST endpoint URL | |
| user_aliases | Yes | Array of user aliases to create |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It implies a write operation but says nothing about required auth/permissions, whether creation is idempotent on repeated alias_name+alias_label, what happens on conflict, or the batch ceiling (the schema's maxItems=50 is never surfaced).
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 tightly-worded sentence with the action front-loaded and no filler. It could arguably be split to carry an alternative-tool pointer, but as written nothing is wasted.
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 parameterized mutation tool with no annotations and no output schema, the definition is minimal but not misleading. It omits auth expectations, batch/rate behavior, and behavior on alias collision, leaving real gaps an agent would want before invoking it.
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 the baseline is 3. The phrase 'existing users or create alias-only profiles' does add meaning by implicitly explaining why external_id is optional, but the description gives no syntax, format, or constraint detail beyond what the schema already documents.
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+resource ('Create new user aliases') and even distinguishes two modes of operation (attaching to existing users vs. creating alias-only profiles). It does not, however, differentiate itself from the closely-named sibling users_alias_update, which is the highest-risk confusion point.
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 when-to-use guidance beyond the implicit 'create' semantics. It never names users_alias_update (the obvious alternative for modifying an existing alias) or users_identify as the path when the alias needs to be linked to a known external_id. The reader must infer the choice from sibling names alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.