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

Since no annotations are provided, the description carries the full burden. It discloses key behaviors: size limit (16KB max), namespace ownership on first write, required token, and pricing. However, it does not mention overwrite behavior or error conditions, which slightly reduces transparency.

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 very concise, consisting of two clear sentences plus a pricing line. It front-loads the core purpose and includes essential details without any redundant information. Every sentence contributes value.

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 no output schema, the description does not mention return values or error handling. It covers namespace ownership, key/value specifics, and cost, but misses overwrite behavior and success response. This leaves the agent with some uncertainty for a write 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 coverage is 100%, so the baseline is 3. The description adds minimal extra meaning, such as the token being set on first write. The schema descriptions already cover the parameters adequately, so the description provides limited additional semantic value.

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 purpose: 'durable key-value storage that survives between agent runs' and 'Write a JSON value under a key'. It distinguishes itself from the sibling 'memory_get' by being a write operation, and provides context about namespace ownership and token usage.

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 implies usage for persisting data across runs but lacks explicit guidance on when to use this tool versus alternatives like 'memory_get' or other storage tools. There is no when-to-use or when-not-to-use statement, leaving the agent to infer context.

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