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

The description adds scoping behavior beyond the readOnly/idempotent annotations: 'Scoped to your identifier (anonymous IP, BYO key hash, or account ID).' It also clarifies the optional-key listing behavior. No contradiction with annotations exists, and this context enriches the agent's understanding of the tool's operational boundaries.

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?

Two sentences, each dense with purpose and context. The action is front-loaded, and every clause contributes value—no redundant phrasing or filler. It is an exemplary concise tool description.

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 1-parameter memory lookup with strong annotations, the description covers purpose, usage, scoping, and sibling relationships in a compact space. No output schema exists, but the description clearly implies the return values (the value or the key list), making it complete for the tool's complexity.

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% and the schema already documents the key property ('Memory key to retrieve (omit to list all keys)'). The description adds the contextual link to remember and forget, but no additional syntax or format details beyond what the schema already provides, so it only marginally enhances parameter understanding.

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+resource: 'Retrieve a value previously saved via remember, or list all saved keys (omit the key argument).' This clearly distinguishes it from the sibling tools remember and forget by defining its exact output behavior, leaving no ambiguity about what the tool does.

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 explicitly states 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 frames the workflow with 'Pair with remember to save, forget to delete,' giving clear relational guidance on how it fits with sibling tools.

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