Vultr MCP

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

With no annotations provided, the description carries the full burden. It discloses that this is a creation/mutation tool ('Create a new firewall rule') and provides parameter constraints (e.g., port required for certain protocols), but lacks critical behavioral details like required permissions, whether the rule takes effect immediately, rate limits, or error conditions.

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, Examples) and front-loaded purpose. While comprehensive, some details in the parameter explanations could be more concise, but overall it avoids unnecessary verbosity.

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 creation tool with 8 parameters, 0% schema coverage, no annotations, but with an output schema, the description does well by thoroughly documenting parameters and providing examples. However, it lacks behavioral context (permissions, side effects) that would be important for a mutation tool, keeping it from a perfect score.

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?

Given 0% schema description coverage, the description fully compensates by explaining all 8 parameters with clear semantics, examples, and constraints (e.g., 'subnet_size: Subnet size (0-32 for IPv4, 0-128 for IPv6)', 'port: Port or port range... - required for tcp/udp'). This adds significant value beyond 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 ('Create a new firewall rule') and identifies the resource ('firewall rule'). It distinguishes from sibling tools like 'delete_rule', 'get_firewall_rule', and 'list_firewall_rules' by specifying creation rather than retrieval or deletion.

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 parameter documentation (e.g., 'required for tcp/udp') and examples showing specific scenarios, but lacks explicit guidance on when to use this tool versus alternatives like 'setup_web_server_rules' or 'delete_rule'. No prerequisites or exclusions are mentioned.

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