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 the tool returns a 'summary with service breakdown', which adds some behavioral context, but fails to disclose critical details like whether it's read-only, requires authentication, has rate limits, or what the output format entails. For a tool with zero annotation coverage, this is inadequate.

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 front-loaded with the core purpose in the first sentence and adds a brief return statement. It's appropriately sized with no wasted words, though the return statement could be integrated more seamlessly. Overall, it's efficient and well-structured.

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 (a summary retrieval with no output schema) and lack of annotations, the description is incomplete. It mentions the return includes a 'service breakdown', but doesn't specify data format, timezone, or what 'usage and cost' entails. Without annotations or output schema, more detail is needed for the agent to use it effectively.

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 tool has 0 parameters with 100% schema description coverage, so the schema fully documents the inputs. The description doesn't need to add parameter semantics, and it appropriately avoids discussing parameters. A baseline of 4 is given since no parameters exist, and the description doesn't introduce confusion.

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 with a specific verb ('Get') and resource ('current month usage and cost summary'), and distinguishes it from siblings like 'get_last_month_summary' by specifying 'current month'. However, it doesn't fully differentiate from 'get_monthly_usage_summary' or 'get_usage' in terms of scope or detail.

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 'get_last_month_summary', 'get_monthly_usage_summary', or 'get_usage'. It lacks context about prerequisites, timing, or specific use cases, leaving the agent with no usage differentiation.

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