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 covered. The description adds valuable behavioral context: listing all keys when omitted, scoping to a user identifier, and the relationship to remember/forget. It does not describe the return format or behavior on missing keys, but given the simplicity and annotation coverage, this is sufficient.

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 remarkably concise: two sentences front-load the core behavior, then add usage examples and scoping. Every sentence contributes meaningful information, with no redundancy or filler.

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 nearly complete. It explains the retrieval and listing modes, provides usage context, and notes scoping. The only minor gap is the lack of explicit return value details, but the description's 'Retrieve a value' and the schema's listing hint make the expected output clear enough.

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% (key is described as 'Memory key to retrieve (omit to list all keys)'). The description enriches semantics with concrete examples of stored values (target ticker, address, research notes) and clarifies the omission behavior, going slightly beyond the bare schema description.

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: 'Retrieve a value previously saved via remember, or list all saved keys (omit the key argument).' It also distinguishes from sibling tools by explicitly pairing with 'remember to save, forget to delete.' This provides a specific verb+resource and differentiates from nearby memory tools.

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 usage context: '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 names alternatives (remember, forget) and mentions scoping to an identifier. This fully covers when and how to use the tool relative to its siblings.

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