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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the description is not burdened with stating these. It adds valuable behavioral context about scoping ('Scoped to your identifier') and the optional list-all-keys behavior, which goes beyond what annotations convey. However, it does not disclose return format or potential errors, but this is minor for a read-only lookup.

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, front-loaded with the core function. Every sentence adds value: the first states the action, the second gives usage rationale and examples, and the third provides scoping and pairing with related tools. There is no 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 tool with one optional parameter and no output schema, the description covers purpose, usage, scoping, and relationships with sibling tools. Annotations handle safety semantics, and the description provides enough behavioral context for an agent to select and invoke the tool appropriately.

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%, so the baseline is 3. The description enhances parameter meaning by providing realistic examples of 'key' values and restating the omit-to-list behavior, which reinforces the schema. It also adds context about scoping that clarifies how keys are stored, giving more semantic depth than the schema alone.

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 uses specific verbs 'Retrieve' and 'list' with a clear resource ('a value previously saved via remember' and 'all saved keys'). It distinguishes the tool from siblings by explicitly naming related tools 'remember' and 'forget', making its role in the memory workflow unambiguous.

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 explicitly states when to use the tool: 'Use to look up context the agent stored earlier' and provides concrete examples (target ticker, address, research notes). It also implies the alternative of re-deriving information ('without re-deriving it from scratch') and pairs with 'remember' and 'forget', giving clear usage context.

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