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

Annotations already cover idempotency, non-destructiveness, and write operation. The description adds valuable context about scoping by identifier, persistence differences between authenticated (persistent) and anonymous (24-hour TTL) users, and the key-value storage model. This goes beyond the annotations and provides meaningful behavioral detail, though it could mention overwrite behavior or failure modes.

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 sentences, front-loaded with the core purpose, followed by usage guidance, storage details, and sibling tool pointers. Every sentence adds distinct value without redundancy. It is concise yet thorough, making it easy for an agent to parse quickly.

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 memory-write tool, the description covers all essential aspects: intended use, key-value structure, scoping, persistence semantics, and relationships to recall/forget. No output schema is needed, and the complexity is low. The description is complete enough for an agent to invoke the tool correctly without further clarification.

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 input schema has 100% coverage for both parameters, including descriptions and examples. The description adds a few usage examples (e.g., 'resolved ticker', 'target address') but does not provide substantive semantic enhancement beyond the schema. Following the baseline for high schema coverage, a score of 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 clearly states the tool's function: 'Save data the agent will need to reuse later' – a specific verb with a resource. It distinguishes itself from sibling tools by mentioning persistence across conversations/sessions and by explicitly pairing with recall and forget. This makes the purpose unambiguous and differentiates it from other 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?

The description provides explicit guidance on when to use the tool: 'Use when you discover something worth carrying forward' with concrete examples like a resolved ticker or user preference. It also hints at when not to use it (i.e., for transient data) and directs to alternatives ('Pair with recall... forget to delete'). This fully addresses usage context.

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