create_env_var

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

No annotations are provided, so the description must convey behavioral traits. It mentions that 'type' defaults to 'encrypted' and explains 'target', which is helpful. However, it does not disclose what happens if the variable already exists (e.g., error or overwrite), authentication needs, or response format. This is a moderate gap for a mutation tool.

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 two sentences long, front-loaded with the main purpose, and contains no extraneous information. Every word contributes to understanding.

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 lack of an output schema and annotations, the description is incomplete for a creation tool. It does not explain return values, error behavior (e.g., duplicate variables), or prerequisites. While the parameters are well-covered by the schema, behavioral gaps remain, making it adequate but not thorough.

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 100%, so the schema already describes all parameters. The description adds value by clarifying the meaning of 'target' (production/preview/development) and the default for 'type'. This improves understanding but does not significantly exceed what the schema provides, resulting in a baseline score.

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 clearly states 'Create an environment variable on a project', which is a specific verb-resource pair. This distinguishes it from siblings like update_env_var (update) and bulk_create_env_vars (bulk creation).

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 usage by explaining target and type default, but it does not explicitly state when to use this tool versus alternatives like bulk_create_env_vars for multiple variables or update_env_var for modifications. No prerequisites or exclusions are mentioned.

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