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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is known. The description adds valuable behavioral context about scoping to an identifier and the dual behavior of retrieving a single value vs. listing all keys when the key argument is omitted. This goes beyond what annotations alone provide, though it doesn't describe error handling or return formats.

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 that front-load the main purpose and then provide usage context, scoping, and related tools. Every sentence adds value, with no fluff or redundant information. It is structured logically: function, use case, and ecosystem.

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 low complexity (one optional parameter, no output schema), the description covers all necessary aspects: what it does, when to use it, how it scopes data, and how it relates to the memory system (remember/forget). It is complete and self-contained for an agent to decide invocation.

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 single 'key' parameter is fully documented in the schema with 'Memory key to retrieve (omit to list all keys)'. The description repeats this and adds examples of key types, but the core semantics are already present. Since the schema carries the heavy lifting, a baseline of 3 is appropriate; the extra examples are helpful but not transformative.

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)'. It uses specific verbs (retrieve/list) and explicitly distinguishes itself from sibling tools like remember and forget by naming them and describing the relationship.

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 gives explicit usage context: '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 names the complementary tools 'remember' and 'forget', providing a clear when-to-use vs alternatives. The scoping detail ('Scoped to your identifier') adds important context for the agent.

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