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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only mentions that value must be a string or JSON serializable, but does not disclose whether writes overwrite existing keys, how TTL behaves, or whether a session is auto-created. This is a mutation tool where such details are important.

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 that front-loads the primary action. There is no filler or redundant information. It efficiently communicates the core purpose.

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?

With no output schema and no annotations, the description is incomplete for a write tool. It fails to explain return values, overwrite semantics, TTL behavior, or any error conditions. The provided information is only minimally sufficient to understand what the tool does, not how it behaves in practice.

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 coverage is 100%, with all four parameters already having descriptions. The description adds no new parameter semantics beyond repeating the value type constraint already present in the schema. Baseline of 3 is appropriate since the schema does the heavy lifting.

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 action: '세션에 키-값을 저장합니다' (stores key-value in session). This is a specific verb+resource that distinguishes it from sibling tools like scratchpad_read, scratchpad_delete, and scratchpad_list, which handle other operations.

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 description provides no guidance on when to use this tool versus alternatives. It does not mention conditions, prerequisites, or any explicit exclusion criteria. The context of sibling tools is present in the signal, but the description itself offers no usage direction.

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