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

The description adds substantial behavioral detail beyond annotations: the value is never returned to the AI, it calls variableUpsert with skipDeploys:true, does not invoke deployment, changes can affect later deployments, and only confirmation plus variable name are returned. This is rich context for a destructive 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 front-loaded with the operation and then layers prerequisites and side effects. It is efficient, though slightly verbose with separate sentences for related deployment behavior.

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?

It covers the mutation's secret handling, approval requirement, return format, and deployment side effects well. However, given 11 parameters with no schema descriptions and no output schema, it leaves significant parameter semantics unexplained, making it only partially complete.

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 0% across 11 parameters. The description only implicitly covers projectId, environmentId, serviceId, and name, while approval_id and numerous beon_* parameters are left undocumented in both schema and description. It does not compensate for the coverage gap.

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 states a specific verb (create/overwrite) and resource (Railway variable) with scope (project, environment, optional service). It is clear but does not explicitly differentiate from sibling tools such as railway_delete_variable or railway_list_variable_names.

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?

It provides clear usage context: the value must be entered privately in BEON PASS and exact user approval is required. It does not name alternatives or state when not to use this tool, but the prerequisites are well specified.

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