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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is known. The description adds meaningful context beyond that, including the scoping to the user's identifier and the dual behavior of retrieving a specific value versus listing all keys based on the presence of the key argument.

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, each earning its place. It front-loads the core function, then provides use-case context, scoping, and tool relationships. No filler or repetition.

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?

There is no output schema, so the description bears some responsibility for return values. It implies the return of a value or list of keys, and covers scoping and pairing. However, it does not specify behavior for a missing key or the exact format of the key list, leaving a minor gap.

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% for the single key parameter, and the schema already describes 'omit to list all keys.' The description enhances this by giving examples of key content (user's target ticker, address, research notes) and reinforces the omit-to-list behavior, adding value beyond the schema.

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 with a specific verb and resource: 'Retrieve a value previously saved via remember, or list all saved keys.' It also distinguishes itself from siblings by naming remember and forget as paired companions, and provides concrete examples of the kind of context to look up.

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 gives explicit when-to-use guidance: 'Use to look up context the agent stored earlier... without re-deriving it from scratch.' It also names alternatives/related tools ('Pair with remember to save, forget to delete'), covering the relationship between operations.

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