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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, establishing the tool as safe and idempotent. The description adds value by explaining the dual behavior (retrieve by key or list all when key is omitted) and the scoping mechanism. While it doesn't contradict annotations, it could provide more detail about error cases or return format.

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 concise at three sentences. It is front-loaded with the primary action and efficiently covers purpose, usage, and scoping without unnecessary words. Every sentence contributes meaningful information.

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?

For a simple tool with one optional parameter and no output schema, the description is largely complete. It explains the two modes (retrieve/list), scoping, and typical use cases. However, it does not explicitly state that the return value is the saved value or a list of keys, nor does it mention error behavior (e.g., key not found). Given the simplicity, this is 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% and the schema description for 'key' already explains its behavior ('omit to list all keys'). The description adds semantic context by providing examples of keys ('user's target ticker, an address, prior research notes'), which helps the agent understand what kind of data is retrievable. This goes beyond the schema's structural definition.

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: 'Retrieve a value previously saved via remember, or list all saved keys (omit the key argument).' It uses specific verbs (retrieve/list) and identifies the resource (saved memory values). It also distinguishes itself from sibling tools like 'remember' and 'forget' by naming them explicitly.

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 provides excellent usage guidance. It tells the agent when to use this tool: '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 mentions scoping ('anonymous IP, BYO key hash, or account ID') and explicitly pairs it with 'remember' and 'forget' for a complete workflow.

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