list_plans

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

The annotation readOnlyHint=true already signals a safe read operation. The description adds the valuable behavioral detail that the tool is public and requires no authentication, which is not inferable from annotations alone.

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 a single concise sentence that immediately states the action, the object, and the key qualifiers (pricing, specs, OS images, public, no auth). Every word earns its place with no redundancy.

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 simple read-only list with no parameters and no output schema, the description provides sufficient context: what is listed and the auth requirement. It does not detail return format, but that is not essential for a public catalog lookup and output schema absence lowers the burden.

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 zero parameters, and the schema fully covers this (100% coverage). The description adds no parameter-specific semantics, but with no parameters this is unnecessary; the baseline of 4 is appropriate.

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 uses a specific verb 'List' and a clear resource 'available VPS plans', further detailing that it includes pricing, specs, and OS images. This clearly distinguishes it from sibling tools like list_vps, which likely lists user-owned VPS instances.

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 notes 'Public — no auth', giving clear context that this tool can be used without authentication, unlike many siblings that likely require auth. It implies when to use it (when browsing available plans) but does not explicitly name alternatives or exclusions.

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