Authenticate with the Verdaccio registry using username and password to obtain a Bearer token for secure access.
Authenticate with the Verdaccio registry using username and password. Returns a Bearer token.
| Name | Required | Description | Default |
|---|---|---|---|
| password | Yes | Verdaccio password | |
| username | Yes | Verdaccio username |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. It usefully discloses the return value (a Bearer token), which matters since there is no output schema. However, it is silent on invalid-credential behavior, token lifetime, and any auth or rate-limit constraints.
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 tight sentences with zero waste, front-loading the action and following with the return value. Nothing is redundant or padded.
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 simple two-parameter auth tool, the description covers the essentials and compensates for the missing output schema by naming the returned token. It falls short on error behavior and token lifecycle, which an agent calling it may need to know.
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 parameters (username, password) are already fully documented in the schema. The description merely restates that username and password are used, adding no new semantics; 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 (authenticate) and resource (Verdaccio registry) plus the credentials used, so the operation is immediately clear. It does not, however, distinguish itself from the sibling create_token, which may also yield a token — a differentiation an agent would benefit from.
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 says nothing about when to call login versus alternatives such as create_token, add_user, or list_tokens. Usage is only weakly implied by the action itself; no prerequisites or exclusions are given.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.