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 mentions the tool returns a 'service-wise cost breakdown with percentages,' which gives some output context, but lacks critical details such as whether this is a read-only operation, any authentication requirements, rate limits, or data freshness. For a tool with zero annotation coverage, this leaves significant gaps in understanding its behavior.

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 and front-loaded with the core purpose, followed by clear sections for arguments and returns. It's concise with no wasted words, though the formatting with separate sections could be slightly more integrated for optimal 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 the tool's low complexity (1 parameter, no output schema, no annotations), the description is minimally adequate. It covers the purpose, parameter, and return value, but lacks depth in behavioral context and usage guidelines, which are important for a cost analysis tool in a server with many siblings. It meets basic needs but doesn't fully compensate for the absence of structured data.

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 description includes an 'Args' section that explains the 'days' parameter as 'Number of days to analyze (default: 30),' adding meaning beyond the input schema, which has 0% description coverage. However, with only one parameter, the baseline is high, and this explanation is adequate but not exceptional, as it doesn't cover edge cases or units beyond what's implied.

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: 'Get cost breakdown by service for the specified period.' It uses a specific verb ('Get') and resource ('cost breakdown by service'), making the function unambiguous. However, it doesn't explicitly differentiate from sibling tools like 'analyze_costs' or 'get_cost_analysis', which appear related, 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. With sibling tools like 'analyze_costs' and 'get_cost_analysis' present, there's no indication of how this tool differs or when it should be preferred, leaving the agent to guess based on names alone.

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