set_environment_variable

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

With no annotations, the description carries the full behavioral burden. It discloses only that the value applies to subsequent requests; it omits overwrite behavior, whether the variable survives across sessions, auth requirements, and failure modes 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?

A single tight sentence with the key effect front-loaded and no wasted words. It is efficient, though brevity here comes partly at the cost of completeness.

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 mutation tool with no annotations, no output schema, and two undocumented required parameters, the description is too thin. An agent lacks the information needed to call it correctly or distinguish it from its sibling set_environment.

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 only 33% (only workspaceRoot is documented). The description says nothing about 'name' or 'value' semantics, formats, or constraints, so it does not compensate for the missing schema documentation.

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?

States a specific verb and resource ('Set a session variable') and adds scope ('for subsequent requests'), so an agent knows it writes a mutable value. However, it gives no differentiation from the sibling 'set_environment', whose relationship to this tool is left to inference.

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 phrase 'for subsequent requests' hints that the effect is session-scoped, but there is no explicit when-to-use, when-not-to-use, or alternative (e.g. set_environment vs set_environment_variable). No prerequisite or ordering guidance is given.

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