create_subscriber_tagCreates a private subscriber tag on your publication to group subscribers without exposing labels to them. Use tags to organize audiences and later assign subscribers.
New private tag for grouping subscribers.
Creates a subscriber tag on your publication. Tags are private: subscribers never see them. Put subscribers under it with tag_subscribers.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | Tag name, e.g. Early readers. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare this is a non-read-only, non-destructive, non-idempotent, open-world write. The description adds genuinely non-structured context that subscribers never see the tags, which matters for how an agent reasons about the effect of the call. It stops short of saying what happens when a tag with the same name already exists (relevant given idempotentHint=false).
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, front-loaded with the identity of the resource, followed by the privacy caveat and next step. No filler.
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 one-parameter creation tool with full annotations, the description covers purpose, privacy semantics, and the natural next call. The only gap is return behavior (no output schema exists), leaving the agent unsure whether a tag ID is returned.
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?
There is a single required parameter with 100% schema description coverage, so the schema already carries the semantics. The description adds nothing about the name parameter beyond the schema's own example ('Early readers'), so baseline 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?
States a specific verb and resource: 'Creates a subscriber tag on your publication,' with the added scope that the tag only groups subscribers. This implicitly separates it from create_post_tag, but it never names the sibling, so the differentiation is inferred rather than stated.
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?
Gives clear follow-up context: build the group with 'tag_subscribers' after creating the tag, which points to a specific sibling. It does not state exclusions or when a different tagging tool (e.g. create_post_tag) would be the right choice.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.