List Vars

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

The annotation readOnlyHint=true already declares that this is a read-only operation, and the description ('List') is consistent. However, the description adds no additional behavioral context beyond the annotation, such as whether credentials are returned masked or the possibility of pagination.

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 with no redundant words or irrelevant information. It is well-structured and front-loaded with the verb and object, making it immediately scannable.

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 tool with no output schema, the description provides minimal context. It does not mention whether the list is filtered by the optional env parameter, whether credentials are included in all cases, or what the response format looks like. Given the presence of sibling tools like getDbCredentials and revealVar, the meaning of 'credentials' is ambiguous.

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?

Schema coverage is 0% (no parameter descriptions), and the description does not compensate. While workspaceSlug and appSlug are self-explanatory from their names, env and region are not explained. The description only hints at 'for an app' and does not clarify the meaning of env (production/preview/development) or region.

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'), names the resource ('environment variables and credentials'), and specifies the scope ('for an app'). This clearly distinguishes it from sibling tools like createVar, deleteVar, and updateVar, which perform different operations.

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 gives no explicit guidance on when to use this tool versus alternatives such as createVar, revealVar, or importVars. While the operation is implied by the name and verb, it does not state conditions like 'use this to retrieve all variables for an app' or mention that createVar is for adding new ones.

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