repl_get_variable

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

The description adds behavioral context by stating the return format: 'JSON with the variable name, type, and serialized value.' This goes beyond the annotations (readOnlyHint, idempotentHint, destructiveHint) and helps the agent understand what to expect. No contradictions with annotations.

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 highly concise: one sentence stating the action and a brief 'Returns:' line. It is front-loaded with the purpose, contains no fluff, and every sentence earns its place.

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 simple nature of the tool, the description is sufficiently complete. It states the purpose, return format, and the annotations cover safety (read-only, idempotent, non-destructive). It does not mention error cases or session validity, but these are not critical for a basic get by ID operation.

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% for the top-level parameter, but the nested schema provides descriptions for var_name and session_id. The description mentions 'variable' and 'session' which adds some semantic context, but it does not explicitly explain the params object or the relationship between the two fields. Description partially compensates for the low coverage.

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 function: 'Retrieve the full value of a variable from a session.' It uses a specific verb ('retrieve') and resource ('variable from a session'), which distinguishes it from related tools like repl_set_variable or repl_delete_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 explicit guidance is provided on when to use this tool versus alternatives. While the verb 'retrieve' implies reading, there is no mention of use cases, exclusions, or comparisons to sibling tools like repl_list_namespace. The description lacks context for choosing this tool.

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