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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds valuable context beyond annotations: the scoping mechanism (anonymous IP, BYO key hash, account ID) and the dual retrieve/list behavior. It does not mention error scenarios, but the added context is meaningful.

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 three sentences, front-loaded with the main action. It includes examples and scoping info, each sentence earning its place. It is slightly more verbose than strictly necessary but remains efficient and structured.

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?

The tool is simple with one optional parameter and no output schema. The description covers purpose, usage scenarios, scoping, and relationship to siblings. It does not describe the return format, but for a simple retrieval tool this is acceptable and the description is otherwise complete.

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 100% — the schema already says 'Memory key to retrieve (omit to list all keys)'. The description reiterates this behavior but adds no new parameter-level detail beyond what the schema provides. Baseline 3 is appropriate.

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 retrieves a value previously saved via remember or lists all saved keys when the key argument is omitted. It includes concrete examples of use cases and distinguishes itself from related siblings (remember and forget) by explicitly pairing with them.

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?

Provides explicit usage context: use it to look up previously stored context (target ticker, address, research notes) without re-deriving it. It also clarifies how to invoke the list behavior (omit the key) and notes scoping to the caller's identifier, which helps determine when to use this tool.

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