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

Annotations already mark the tool as read-only and idempotent; the description adds the key behavioral trait of scoping to an identifier (anonymous IP, BYO key hash, or account ID) and the ability to list all saved keys when the key is omitted, enriching the agent's understanding beyond the safety hints.

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 pack the core operation, usage context, scoping, and related tools without redundancy. Every clause earns its place and the description is front-loaded with the main action.

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-optional-parameter read tool with adequate annotations and no output schema, the description fully covers behavior, scoping, and relationships to remember/forget. There are no missing pieces.

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?

The schema already fully documents the optional 'key' parameter with a description matching the tool's behavior, so schema coverage is 100%; the description adds example key values ('user's target ticker, an address, prior research notes') which gives semantic context but doesn't change the parameter's meaning. Baseline 3 is appropriate.

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 precise verb phrase: 'Retrieve a value previously saved via remember, or list all saved keys,' clearly distinguishing the read operation from the sibling 'remember' (save) and 'forget' (delete) tools. It also explicitly states the two modes of operation, making the tool's purpose unambiguous.

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 instructs when to use: 'Use to look up context the agent stored earlier ... without re-deriving it from scratch,' and names the paired tools 'remember' and 'forget,' which clarifies the workflow and alternatives. It also describes scoping to the user's identifier, providing additional usage context.

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