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

Annotations already provide readOnlyHint=true and destructiveHint=false, and the description adds valuable context beyond that: 'Scoped to your identifier (anonymous IP, BYO key hash, or account ID)' and the dual-mode behavior of omitting the key to list all keys. These are meaningful behavioral disclosures not present in annotations.

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 four sentences, each with a distinct purpose: the core action, usage context, scoping, and companion workflow. It is front-loaded with the primary action and contains no redundant or filler content.

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 sufficiently explains the return behavior (value or list of keys), scoping, and how it fits with remember and forget. The agent has enough context to select and invoke the tool correctly.

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 description restates the schema's parameter description ('omit the key argument' matches the schema's 'omit to list all keys'). Schema coverage is 100%, so the baseline is 3; the description adds no extra format or syntax details for the key parameter.

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 verb and resource: 'Retrieve a value previously saved via remember, or list all saved keys'. It clearly distinguishes from siblings by referencing remember and forget, and provides concrete usage examples ('user's target ticker, an address, prior research notes').

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?

It gives a clear when-to-use: '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 pairs with companions ('Pair with remember to save, forget to delete'), but does not explicitly state when not to use or list alternative tools for the same purpose.

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