vercel_create_env

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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It mentions the upsert behavior, default target, and type options, which are useful. However, it does not mention authentication requirements, rate limits, idempotency, or error scenarios. The description covers core behaviors but misses some important details.

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 extremely concise—only two sentences—and front-loads the main purpose. Every sentence adds value without redundancy. There is no fluff or unnecessary detail.

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 tool's complexity (10 parameters, no output schema, no annotations), the description is fairly complete for the core functionality: it explains the action, defaults for target and upsert, and type usage. However, it omits explanations for git_branch, comment, team_id, api_key, and does not describe the response format or any potential side effects. It meets minimal viability but has clear gaps.

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 description coverage is 30% (only target, type, upsert have descriptions). The description adds meaning by explaining that 'Target defaults to production, preview, and development' and that 'type' should be 'plain' for non-secrets and 'encrypted' or 'sensitive' for secrets. However, it does not compensate for the 70% of undocumented parameters like project_id, key, value, git_branch, comment, team_id, and api_key. The added value is moderate.

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 the tool's purpose: 'Create (or upsert) an environment variable on a Vercel project.' It uses a specific verb ('create/upsert') and resource ('environment variable'), which effectively distinguishes it from sibling tools like vercel_get_env, vercel_delete_env, and vercel_list_deployments.

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 does not explicitly state when to use this tool versus alternatives. It provides guidance on parameter values (e.g., type for secrets) but lacks information on prerequisites, such as requiring a project_id and api_key, or when to prefer other Vercel env tools. No comparison with get_env or delete_env is given.

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