Vultr MCP

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries full burden for behavioral disclosure. It clearly indicates this is a read operation (listing users) and provides detailed return value information, which is helpful. However, it doesn't mention pagination behavior, rate limits, authentication requirements, or whether the list is filtered/sorted, leaving some behavioral aspects unspecified.

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 description is efficiently structured with a clear purpose statement followed by detailed return value documentation. Every sentence adds value, though the return value section could be slightly more concise by omitting deprecated fields or grouping related information. Overall, it's well-organized and appropriately sized.

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 listing tool with 0 parameters and an output schema (implied by the detailed return documentation), the description is quite complete. It provides the core purpose and comprehensive return value details. The main gap is lack of behavioral context like pagination or rate limits, but given the tool's simplicity and the presence of return documentation, it's mostly adequate.

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?

The input schema has 0 parameters with 100% description coverage, so no parameter documentation is needed. The description appropriately doesn't discuss parameters, focusing instead on the return values. This meets expectations for a parameterless tool, though it doesn't explicitly state there are no parameters.

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 specific action ('List all users') and resource ('in your Vultr account'), providing a complete purpose statement. It distinguishes itself from sibling tools like 'get_user' (which retrieves a single user) and 'create_user' (which creates new users), establishing its unique role as a comprehensive listing operation.

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 implies usage when needing a complete list of users, but doesn't explicitly state when to use this tool versus alternatives like 'find_by_email' or 'find_by_name' for specific user lookups. There's no guidance on prerequisites, rate limits, or access requirements, leaving usage context somewhat incomplete.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.