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. While 'Stop' implies a state-changing operation, it doesn't specify whether this is reversible, what permissions are required, whether data is preserved, or what happens to associated resources. The description mentions a return value but doesn't describe error conditions or side effects.

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 (purpose, args, returns) and uses only three sentences. However, the 'Args:' and 'Returns:' headings are slightly redundant since the schema already documents parameters and return types, making it not perfectly efficient.

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 destructive operation with no annotations, the description is moderately complete. It covers the core purpose and parameter semantics well, and the existence of an output schema means it doesn't need to detail return values. However, it lacks important behavioral context about safety, reversibility, and error conditions that would be expected for a stop operation.

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?

With 0% schema description coverage for the single parameter, the description provides essential semantic context that the schema lacks. It explains that 'instance_id' accepts multiple identifier types (ID, label, hostname, or UUID) with concrete examples, which is crucial information not present in 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 specific action ('Stop') and resource ('a running instance'), distinguishing it from sibling tools like 'start', 'reboot', or 'delete'. It provides a complete verb+resource combination that leaves no ambiguity about the tool's function.

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 like 'stop_bare_metal_server', 'stop_migration', or other stopping mechanisms. It doesn't mention prerequisites, dependencies, or contextual constraints for proper usage.

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