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 valuable behavioral context beyond these: the scoping detail ('Scoped to your identifier (anonymous IP, BYO key hash, or account ID)') and the behavior of listing all keys when the key argument is omitted. This enriches agent understanding of the tool's operational boundary.

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 composed of four sentences, each earning its place: core action (first sentence), use cases (second), scoping (third), and sibling relationship (fourth). It is front-loaded with the main verb and contains no filler or redundant 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 read-only tool with one optional parameter, strong annotations, and no output schema, the description covers purpose, usage scenarios, scoping, and related tools. It does not specify return format or error behavior, but the tool's low complexity and rich annotations make this a minor gap rather than a critical omission.

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%: the only parameter 'key' already has a description ('Memory key to retrieve (omit to list all keys)'). The tool description reinforces this with examples and restates the omit-to-list behavior, but adds no new syntax, format, or edge-case details beyond what the schema already provides. Baseline 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 clearly states the tool's action with a specific verb and resource: 'Retrieve a value previously saved via remember, or list all saved keys'. It explicitly distinguishes between retrieval and listing, and names sibling tools (remember, forget), which differentiates it from alternatives.

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 usage context: 'Use to look up context the agent stored earlier' and gives concrete examples (target ticker, address, research notes). It also names alternatives by saying 'Pair with remember to save, forget to delete', which clarifies when to use this tool versus its siblings.

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