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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds beyond this by disclosing scoping ('Scoped to your identifier (anonymous IP, BYO key hash, or account ID)') and the dual-mode behavior (retrieve by key or list all keys). This is useful context not present in the annotations, though it does not detail return formats or error cases.

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 serving a distinct purpose: first defines the core action, second gives the use case and examples, third explains scoping and partnerships with remember/forget. Information is front-loaded and there is no redundant phrasing. It is concise yet informative.

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 (single optional parameter, read-only, no output schema), the description covers its main functionality, usage context, scoping, and related tools. It does not specify the return value shape or behavior when a key is missing, but the absence of an output schema and the clear examples make the description sufficiently complete for an agent to select and 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% and the parameter description already states 'omit to list all keys'. The tool description reiterates the same logic ('omit the key argument') without adding deeper meaning. It offers examples of stored values, but these do not clarify the parameter's syntax or edge cases. Thus it meets the baseline but does not exceed it.

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 starts with a specific action: 'Retrieve a value previously saved via remember, or list all saved keys (omit the key argument).' It clearly identifies the resource (saved memories), the operations (get by key or list), and provides concrete examples (ticker, address, research notes). This distinguishes it from siblings like remember and forget by focusing on retrieval only.

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?

Explicitly states when to use: 'Use to look up context the agent stored earlier — the user's target ticker, an address, prior research notes — without re-deriving it from scratch.' It also explains the conditional behavior of omitting the key to list all keys. While it mentions pairing with remember and forget, it does not explicitly state when not to use the tool, so it falls short of a 5.

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