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

Annotations already mark the tool as read-only, idempotent, and non-destructive. The description adds context about scoping to user identifier (anonymous IP, BYO key hash, account ID), which is beyond 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 concise (three sentences), front-loads the main purpose, and efficiently conveys usage, scoping, and relationships without unnecessary 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, read-only, idempotent) and comprehensive annotations, the description covers all essential aspects: dual operation modes, scoping, and tool ecosystem. No output schema needed as return type is implied.

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 description essentially restates the schema's parameter description. It does not add new information about the 'key' parameter beyond what is already in the schema, though it clarifies the behavior of omitting the key.

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 action ('retrieve a value' or 'list all keys'), specifies the resource ('memory key/value'), and distinguishes from sibling tools (remember, forget) by name.

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 describes when to use the tool ('look up context the agent stored earlier') and implies when not to use it (not for saving or deleting). Mentions pairing with 'remember' and 'forget', providing clear alternatives.

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