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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds valuable behavioral context by explaining scoping ('Scoped to your identifier (anonymous IP, BYO key hash, or account ID)') and the dual behavior of listing vs. retrieving. This goes beyond what annotations offer, though it doesn't detail error cases or output format, which is not required for such a simple read tool.

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 with no fluff. The first sentence states the action and modes, the second gives concrete use cases, and the third explains scoping. Information is front-loaded and every sentence contributes value. This is model conciseness.

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 one-parameter, read-only tool with comprehensive annotations and full schema coverage, the description is complete enough. It explains the two call modes, provides usage context, scoping, and related tools. It doesn't specify the exact return format, but 'retrieve a value' and 'list keys' are self-explanatory. With no output schema, a bit more detail on the response could be provided, but the description adequately covers the essential context.

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?

The input schema already describes the 'key' parameter as 'Memory key to retrieve (omit to list all keys)', providing 100% coverage. The description repeats this behavior ('omit the key argument') and adds illustrative examples of key contents, but does not add technical parameter semantics beyond what the schema states. With full schema coverage, a baseline score of 3 is appropriate.

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 a specific action: 'Retrieve a value previously saved via remember, or list all saved keys (omit the key argument).' It clearly identifies the tool's resource (saved memory values) and differentiates modes. It also distinguishes itself from sibling tools by referencing 'remember' and 'forget' as complements, making its role in the memory lifecycle explicit.

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 strong context for when to use the tool: '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 points to alternatives ('Pair with remember to save, forget to delete'), but stops short of explicitly stating when not to use the tool (e.g., for real-time data). This is clear guidance, though not exhaustive.

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