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. It mentions 'smart identifier resolution' and the 'live' parameter with a default, which adds some behavioral context. However, it fails to disclose critical details such as required permissions, potential impacts on the instance (e.g., if 'live' is false, a reboot might be needed), rate limits, or error conditions, 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 a clear purpose statement, parameter explanations, and a return value note, all in a compact format. Every sentence adds value, but it could be slightly more front-loaded by moving the 'Args' and 'Returns' sections into a more integrated narrative for better readability.

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 that this is a mutation tool with no annotations and an output schema exists (implied by 'Returns: Success confirmation'), the description does an adequate job by covering parameters and basic behavior. However, it lacks details on error handling, side effects, and integration with sibling tools, making it incomplete for safe and effective use in complex scenarios.

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. It provides meaningful semantics for all three parameters: 'volume_identifier' and 'instance_identifier' are explained with examples (label/ID/hostname), and 'live' is described with its default and effect ('attach without rebooting'). This adds substantial value beyond the bare schema, though it could include more details like format constraints.

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 verb ('Attach') and resource ('block storage volume to an instance'), making the purpose specific and understandable. However, it does not explicitly distinguish this tool from its sibling 'attach_to_instance', which appears to serve a similar function, leaving some ambiguity about differentiation.

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 through the mention of 'smart identifier resolution' for volume and instance identifiers, suggesting when to use this tool for attachment operations. However, it lacks explicit guidance on when to choose this tool over alternatives like 'attach_to_instance' or 'detach', and does not mention prerequisites or exclusions.

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