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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, reducing the burden. The description adds valuable context beyond those hints: 'Scoped to your identifier (anonymous IP, BYO key hash, or account ID)' and the behavior of listing all keys when key is omitted. This provides a richer behavioral picture without contradicting the 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 three sentences, each earning its place: the first states the core action and listing behavior, the second gives concrete use cases, and the third explains scope and pairing. It is front-loaded with the essential verb and resource, with no wasted words.

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 tool's simplicity (1 optional parameter, no output schema, strong annotations), the description covers all necessary aspects: purpose, usage context, scope/isolation, and relationship to sibling tools. Nothing critical is missing for an agent to invoke it correctly.

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%: the 'key' property already has the description 'Memory key to retrieve (omit to list all keys).' The description reinforces this with examples of realistic key values, but since the schema fully defines the parameter, the added semantic contribution is modest.

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 opens with the specific verb+resource: 'Retrieve a value previously saved via remember, or list all saved keys (omit the key argument).' It distinguishes itself from siblings by naming 'remember' and 'forget' and giving concrete examples ('user's target ticker, an address, prior research notes'), which makes the tool's purpose unmistakable.

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 clearly indicates when to use this tool: 'Use to look up context the agent stored earlier... without re-deriving it from scratch.' It also references sibling tools ('Pair with remember to save, forget to delete'), implying the workflow. However, it does not explicitly state when *not* to use it (e.g., alternatives like search), so it stops short of a full when/when-not contrast.

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