Retrieve a subscription by username to look up subscriber details. Use it when you need to fetch a specific user's subscription from the Remnawave panel API.
GET /api/subscriptions/by-username/{username} Get subscription by username Tags: [Protected] Subscriptions Controller
| Name | Required | Description | Default |
|---|---|---|---|
| username | Yes | Username |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. The embedded 'GET' verb implies a read operation and the '[Protected]' tag weakly hints at authentication, but nothing is stated about permissions, error behavior, or what the response contains. For a protected read endpoint this leaves meaningful gaps.
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?
It is short and the essential statement is first, which is good. However, the raw route path and the generated 'Tags:' line are pure noise that consume space without informing an agent, so it is not as tight as it could be.
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?
This is a simple one-parameter read tool with no output schema, so the description is the only place return shape and failure modes could be conveyed — and it conveys neither. The scope is low-complexity, but the omission of any return-value or error context leaves it incomplete.
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% for the single 'username' parameter, so the schema already documents it. The description adds no additional semantics (format constraints, case sensitivity, whether it must match an existing user) beyond the schema. 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?
The description states a verb+resource ('Get subscription by username'), which is understandable, but it is essentially a restatement of the tool name with a raw endpoint path prepended. It offers no differentiation from near-identical siblings such as subscriptions_get_subscription_by_uuid, subscriptions_get_subscription_by_short_uuid_protected, or users_get_user_by_username. Minimum viable.
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 many sibling subscription/user lookup endpoints. The 'Tags: [Protected] Subscriptions Controller' line is generated metadata rather than actionable usage context. An agent gets no exclusions or alternative routing.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.