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

The description adds the specific behavioral constraint that it lists 'running' services. The annotations already provide safety context (readOnlyHint, destructiveHint), so the description provides moderate, focused value.

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 single sentence is highly efficient, relevant, and front-loaded, achieving maximum communication with minimal words.

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 simple structure and lack of an output schema, the description is adequate. It provides the necessary scope (running preview services) without over-explaining what is already defined in the input schema.

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?

Since schema description coverage is 100%, the schema covers all parameter details. The description merely reiterates the function and does not add any meaningful context to the parameter `project_id`.

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 is clear and uses a specific verb ('List') and resource ('preview services'). It helps distinguish the action, though it doesn't explicitly name a sibling tool it differs from.

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 no guidance on when to use this tool versus alternatives like 'get_preview' or 'list_deployments.' It only specifies the state of the services it handles (running).

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