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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds valuable context about scoping to an identifier (anonymous IP, BYO key hash, or account ID) and the listing behavior when the key is omitted, which goes beyond the annotations. No contradictions.

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 long, front-loaded with the primary action, and every sentence adds distinct value: what it does, when to use it, and how it relates to sibling tools. No redundancy or filler.

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 and no output schema, the description is fully adequate. It covers purpose, usage, scoping, and peer relationships without needing to explain return values or complex behavior. The provided annotations further round out the 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?

Schema description coverage is 100%, and the schema already explains the 'key' parameter well, including the omit-to-list behavior. The description adds illustrative examples of values but does not provide additional parameter syntax or format details, so it aligns with the baseline for full schema coverage.

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 a specific verb ('Retrieve') and resource ('a value previously saved via remember') while also covering the alternative behavior of listing all keys when the key argument is omitted. It clearly distinguishes this tool from its siblings remember and forget.

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 gives concrete examples (target ticker, address, research notes). It also indirectly highlights when to use alternatives by pairing with 'remember to save, forget to delete', and explains the benefit of avoiding re-deriving information.

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