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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is clear. The description adds useful behavioral context about scoping: "Scoped to your identifier (anonymous IP, BYO key hash, or account ID)." It also clarifies the dual behavior of listing all keys when the argument is omitted.

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 concise sentences, each earning its place. The first sentence front-loads the action, the second gives usage context, and the third covers scoping and relationships. No wasted words.

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?

Given the tool's simplicity (one optional parameter, no output schema, strong annotations), the description is complete. It explains the tool's behavior, scope, and relation to remember/forget, leaving no significant gaps for an agent to misuse it.

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 key parameter is described in the schema). The description adds value by providing examples of what keys represent ("user's target ticker, an address, prior research notes") and by explicitly explaining the omit-to-list behavior, which enriches the schema's minimal description.

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 function: "Retrieve a value previously saved via remember, or list all saved keys (omit the key argument)." This specifies the verb (retrieve/list) and resource (saved memory), and distinguishes it from sibling tools like 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 explains when to use the tool: "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 references sibling tools ("Pair with remember to save, forget to delete") but lacks an explicit when-not-to-use condition.

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