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

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds a behavioral fact beyond the annotations: no authentication is required. This is useful context for an agent deciding whether it can call the tool directly.

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, front-loaded sentence that names the resource, the scope, and the authentication requirement. Every part adds information and there is no filler.

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 catalog lookup, the description is complete: it states what is listed, what is included, and the auth requirement. The annotations cover the behavioral safety profile, so nothing critical is missing.

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 input schema is empty with zero required parameters, so there is no parameter semantic burden for the description to carry. The baseline of 4 applies because the schema fully documents the lack of parameters.

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?

States a specific verb 'List', a clear resource ('available VPS hosting locations'), and narrows scope to cities/countries with available packages. This distinguishes it from sibling catalog tools like listVpsPackages and listVpsOsTemplates.

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 when to use it (when discovering VPS locations) and adds a useful context cue with 'No authentication required.' However, it gives no explicit guidance about when not to use it or how it relates to sibling tools.

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