Vultr MCP

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states this is an update operation, implying mutation, but doesn't mention critical details like required permissions, whether changes are reversible, rate limits, or error conditions. The description adds minimal behavioral context beyond the basic action, leaving significant gaps for a mutation tool.

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 well-structured with clear sections (Args, Returns) and uses bullet points for the ACLs list, making it easy to scan. It's appropriately sized for the complexity, though the ACLs list is lengthy but necessary. No extraneous information is included.

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?

Given the tool's complexity (mutation with 3 parameters, no annotations, but with an output schema), the description is fairly complete. It explains all parameters in detail and notes the return value ('Updated user information'), though it could benefit from more behavioral context. The output schema existence reduces the need to fully describe returns, but the lack of annotations means the description should do more to cover safety and usage aspects.

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 0%, so the description must compensate fully. It does so by detailing all three parameters: 'user_id' (explaining it accepts UUID or email), 'api_enabled' (explaining its purpose), and 'acls' (providing a comprehensive list of available permissions with descriptions for each). This adds substantial meaning beyond the bare schema.

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 tool's purpose: 'Update an existing user's settings.' It specifies the resource (user) and the action (update settings), which is specific and actionable. However, it doesn't explicitly distinguish this from sibling tools like 'update_user' or 'update_user_access_control', which appear to serve similar purposes, so it doesn't reach the highest score.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing admin permissions), exclusions, or compare it to sibling tools like 'update_user' or 'update_user_access_control'. The agent is left to infer usage based on the tool name and parameters alone.

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