get_session_variable

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

The annotations already convey readOnly, idempotent, and non-destructive behavior, so the description does not need to restate those. It adds the scoping context of 'user-defined' but does not disclose behavior for missing variables or how session variables relate to the broader session context.

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 concise sentence with no redundant words. It is front-loaded and contains exactly the necessary purpose statement.

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 one-parameter read-only getter, the description combined with the schema and annotations is largely sufficient. It does not explain return behavior for missing variables, but this is a minor gap given the tool's simplicity.

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 schema covers the single 'name' parameter with a clear description, giving 100% schema coverage. The tool description adds little beyond the schema, so it meets the baseline but does not enrich parameter understanding.

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 operation: retrieving a user-defined session variable. It is specific enough about the resource, though it does not explicitly differentiate from sibling tools like get_session_context or set_session_variable.

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?

No guidance is provided on when to use this tool versus alternatives such as set_session_variable, delete_session_variable, or get_session_context. The description only states what the tool does without any usage context or exclusions.

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