update_env

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

No annotations are provided, so the description carries full burden for behavioral disclosure. It only restates the core action without mentioning error handling, whether updates are partial or full, idempotency, or return values. For a mutation tool, this is a significant gap.

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 sentence, immediately front-loaded with the verb and resource, and contains no extraneous information. It is appropriately sized for the tool's simplicity.

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 4-parameter mutation tool with no output schema, the description is adequate but minimal. It omits details about partial update behavior and return values, which could be important for the agent. The schema covers parameters, but the description does not provide additional operational context.

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?

The input schema already describes all four parameters with clear meanings, so the description's mention of 'name/value/remarks' adds no additional insight. The baseline of 3 applies because schema coverage is 100% and the description does not conflict or enhance it.

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 ('Update') with a clear resource ('environment variable') and scope ('by id'). It also lists the fields (name/value/remarks), which distinguishes it from sibling tools like create_env, delete_envs, and list_envs.

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 context is clear that this tool modifies existing environment variables, and the 'by id' phrasing indicates it is for specific instances. However, it does not explicitly state when not to use it (e.g., for creating new variables) or name alternatives, though the verb and sibling tools imply the use case.

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