Fully replace a user profile (PUT). All existing data is overwritten; include every field you want to keep.
| Name | Required | Description | Default |
|---|---|---|---|
| profile | Yes | Complete profile data to replace with | |
| user_id | Yes | The user ID |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate destructiveHint and idempotentHint, but the description adds what gets destroyed: 'All existing data is overwritten.' It also provides practical guidance about including fields to keep, which goes beyond the annotation flags and helps an agent predict side effects.
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 sentences, each earning its place. The core action and method are front-loaded, followed by the critical overwrite warning and the keep-fields guidance. No filler or repetition.
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?
Given the destructive nature, the description sufficiently explains correct usage: provide the full profile. No output schema exists, and the description does not mention return values, but that is not critical for invocation. Minor gaps are the lack of an explicit alternative mention and no error/permission context, but annotations cover idempotence and destruction.
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 coverage is 100% and both parameters have descriptions. The description adds meaning to the 'profile' parameter by explaining that the provided data must be complete, reinforcing that omitted fields will be lost. This is valuable beyond the schema's 'Complete profile data to replace 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?
The description clearly states the action ('Fully replace'), the resource ('a user profile'), and the HTTP method ('PUT'). It distinguishes this from sibling tools like patch_profile by emphasizing full replacement and overwrite semantics.
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 makes the usage context explicit: use this when you want a full replacement and must include every field to keep. It does not explicitly name patch_profile as the partial-update alternative, but the PUT/full-replace language gives clear context without exclusion.
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.
Tools are mostly organized as distinct resource/action pairs, but several clusters are easy to confuse: list subscription tools (add_subscribers_to_list vs bulk_subscribe_to_list vs subscribe_user_to_list), message vs message-content vs message-history retrieval, and the many journey/journey-template list/get tools. Detailed descriptions rescue most selections, but the sheer number of near-identical verb/resource names creates real misselection risk.
Almost all tools follow a snake_case verb_noun pattern (create_, get_, list_, replace_, send_, publish_, archive_). Minor deviations keep it from a perfect score: courier_installation_guide is noun-first, and add_bulk_users sits awkwardly next to the bulk_add_* family, but the overall convention is predictable and readable.
144 tools is an extreme working-set size for an agent to hold and choose from, far beyond the reasonable 3–15 range. Even for a broad platform like Courier, this should be split into focused sub-servers (templates, journeys, users, lists, preferences, etc.) to remain usable.
The surface is remarkably comprehensive, covering sending, templates, journeys, automations, users, tenants, lists, preferences, providers, routing, brands, audiences, translations, digests, bulk jobs, and audit events. Notable gaps exist—automation template CRUD and digest schedule management are missing—but most workflows can still be completed with workarounds.
