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

The description adds meaningful behavioral context beyond annotations: it explains scoping by identifier, persistence for authenticated users, and 24-hour retention for anonymous sessions. It also notes cross-session storage. These details are not present in annotations and help the agent understand the tool's side effects.

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 and well-structured: the first sentence states the core purpose, the second gives usage guidance, the third explains storage scoping, and the final sentence points to related tools. Every sentence adds value with no redundancy.

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 key-value storage tool with no output schema and full schema coverage, the description is complete. It covers what, when, how, retention, and relationships to alternatives, making it fully actionable for an agent.

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?

Input schema already has 100% coverage with descriptions for both key and value. The description adds extra context by explaining the key-value pair semantics and scoping by identifier, which enriches the meaning of the parameters beyond the schema alone.

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 with a specific verb ('Save data') and resource ('data the agent will need to reuse later'), and distinguishes it from siblings by explicitly pairing with recall and forget. Examples of use cases (ticker, address, preference, research subject) further clarify the purpose.

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 provides explicit guidance on when to use the tool ('Use when you discover something worth carrying forward...') and mentions alternatives ('Pair with recall to retrieve later, forget to delete'). This clearly differentiates when to use remember versus sibling tools.

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