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

Annotations already cover readOnlyHint, idempotentHint, and destructiveHint. The description adds the useful fact that no authentication is required and specifies the content returned. It does not disclose pagination, ordering, or whether the list reflects real-time availability, but for a simple read-only list the annotations carry the safety burden.

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 entire description is a single sentence that front-loads the operation name and immediately states the resource and returned attributes. Every word adds value, with no filler or repetition of the schema.

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 zero-parameter, read-only list operation with no output schema, the description covers the key facts an agent needs: what is listed, what is included, and whether authentication is needed. It does not specify the response format, but that is often expected to be a catalog list and the missing details are minor.

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, so the description does not need to explain parameter meaning. The baseline for zero-parameter tools is 4, and the description appropriately focuses on what is returned rather than inputs.

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 resource (available VPS hosting packages) and names the key attributes returned: pricing, specs, and locations. This clearly distinguishes it from siblings like listVpsLocations, listVpsOsTemplates, getVpsPackageDetails, and orderVps.

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 clear context: it is the correct tool for listing available VPS packages with pricing, specs, and locations. It does not explicitly state when not to use it or point to alternatives, but the scope is specific enough that an agent can infer when it applies.

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