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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds valuable behavioral context beyond annotations, particularly the scoping behavior ('Scoped to your identifier') and the listing behavior when omitting the key. It doesn't over-describe but provides meaningful operational detail.

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, front-loaded with the primary purpose, and structured logically: retrieve/list, use case, scoping, and complementary tools. No filler or redundancy; every sentence earns its place.

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, the description fully covers usage, scope, and context. The schema and annotations handle parameter definitions and safety hints, so the description completes the picture without needing return-value details or additional warnings.

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 schema already documents the sole 'key' parameter with 100% coverage, including the omit-to-list behavior. The description reinforces this but doesn't add new parameter-level semantics beyond what the schema provides, so the baseline 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 states the tool's core action with a specific verb ('retrieve') and resource ('value previously saved via remember'), and clearly distinguishes the optional list-all behavior. It also separates itself from siblings by explicitly naming 'remember' and 'forget', eliminating ambiguity.

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 explicit guidance on when to use the tool ('Use to look up context the agent stored earlier...') and names the complementary alternatives ('Pair with remember to save, forget to delete'). This gives the agent a clear decision framework.

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