Vultr MCP

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

No annotations are provided, so the description carries full burden. It states this is a read operation ('get') and mentions the return structure, but lacks critical behavioral details: whether it requires authentication, rate limits, error conditions (e.g., invalid region_id), pagination, or caching behavior. For a tool with zero annotation coverage, this leaves significant gaps in understanding how it behaves.

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 front-loaded purpose. Every sentence adds value: the first states the core function, the Args and Returns clarify I/O, and the final sentence explains utility. It could be slightly more concise by integrating the utility note into the opening, but overall it's efficient with minimal waste.

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, read-only operation) and the presence of an output schema (which covers return values), the description is reasonably complete. It explains the purpose, parameter semantics, and usage context. The main gap is lack of behavioral transparency (e.g., auth needs), but for a simple lookup tool, the description provides sufficient context for basic use.

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 the only documentation for the single parameter 'region_id', including its purpose ('to check availability for') and examples ('ewr', 'lax'). This adds meaningful context beyond the bare schema type. However, it doesn't specify constraints like valid region IDs or format requirements, leaving some ambiguity.

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 availability information for a specific region' with the specific resource being 'availability information' and the verb 'get'. It distinguishes itself from siblings like 'find_regions_with_plan' or 'get_plans_by_region_availability' by focusing on checking availability for a single region rather than searching or listing across regions. However, it doesn't explicitly contrast with these similar tools, preventing a perfect 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 implied usage context: 'This is useful for checking which instance plans are available in a specific region before creating instances.' This suggests when to use it (before instance creation) but doesn't explicitly state when not to use it or name alternatives like 'find_regions_with_plan' for reverse lookups. The guidance is helpful but not comprehensive.

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