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

Annotations already declare safety (readOnly, idempotent, non-destructive). The description adds valuable behavioral context beyond annotations: scoping to agent identifier (anonymous IP, BYO key hash, account ID) and the dual behavior of retrieving a specific key versus listing all keys when argument omitted. 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 compact (3 sentences) and front-loaded: first sentence defines the action, second gives typical usage, third clarifies scope and companions. Every sentence earns its place with no redundancy or fluff.

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 tool with one optional parameter and no output schema, the description is complete: it covers the action, use cases, scope, and relationships to sibling tools. An agent can confidently decide when to invoke this tool without additional 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 already covers the sole parameter with 100% coverage ('Memory key to retrieve (omit to list all keys)'). The description reinforces this by explicitly mentioning the omit behavior and providing concrete examples of key values (ticker, address, research notes), adding practical meaning beyond the schema.

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 purpose: 'Retrieve a value previously saved via remember, or list all saved keys' with specific verbs and resource. It distinguishes itself from sibling tools by naming its companions 'remember' and 'forget' and by explaining it avoids re-deriving context from scratch, setting it apart from research/derivation tools.

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?

Explicitly says 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.' Also names companion tools ('Pair with remember to save, forget to delete') giving clear alternatives for related operations.

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