get_subscriberRetrieve a subscriber's account data from Kit by subscriber ID, optionally selecting a configured private account.
Get a subscriber. Reads account data.
| Name | Required | Description | Default |
|---|---|---|---|
| account | No | Named private account from KIT_ACCOUNTS. Defaults to KIT_DEFAULT_ACCOUNT or the first configured account. | |
| subscriber_id | Yes | Positive subscriber id. |
Changes observed during successful MCP inspections.
v2.0.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the read-only nature is fully covered by structured data. The description adds only the vague "Reads account data," which neither explains error/not-found behavior nor adds any behavioral detail beyond the 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?
The definition is very short and front-loads the purpose, but the second sentence "Reads account data" is filler that does not earn its place and is arguably ambiguous for a subscriber-fetching tool.
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?
With no output schema, the description should ideally indicate what fields a fetched subscriber returns; instead it offers only the ambiguous "account data." For a simple get-by-id tool with a fully documented schema and covering annotations, this is minimally adequate but leaves a visible gap.
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 both subscriber_id and account are already well documented in the schema (including the KIT_ACCOUNTS defaulting behavior). The description adds no parameter meaning beyond that, 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 gives a clear verb+resource ("Get a subscriber") and the singular form implicitly distinguishes it from list_subscribers/search_subscribers. However, the second sentence ("Reads account data") is vague and does not help differentiate it from siblings such as get_subscriber_stats or get_account.
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 alternatives like list_subscribers, search_subscribers, or get_subscriber_stats, nor any stated prerequisites such as whether the subscriber must exist.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.