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

The annotations already provide idempotentHint and destructiveHint, so the description adds value by disclosing scoping ('scoped by your identifier') and retention behavior ('persistent memory' for authenticated users, '24 hours' for anonymous). This goes beyond the structured annotations and gives useful behavioral context.

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 well-organized into four sentences, each serving a distinct purpose: what, when, storage details, and sibling relationships. It is slightly longer than strictly necessary, but every sentence contributes information, so it earns a high but not perfect score.

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 two-parameter memory write tool, the description is complete. It covers purpose, usage context, storage scoping, retention across sessions, and even points to companion tools. Given the minimal schema and lack of output schema, this description fully equips an agent to use the tool correctly.

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%, with both 'key' and 'value' well described. The description reinforces these with examples (e.g., 'resolved ticker', 'target address'), but adds little beyond what the schema already provides. Therefore, it meets the baseline for high schema coverage without significantly expanding parameter meaning.

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 purpose with a specific verb ('Save data') and resource ('key-value pair scoped by your identifier'). It also distinguishes itself from siblings by naming 'recall' to retrieve and 'forget' to delete, making its role in the memory toolset explicit.

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 names alternatives ('Pair with recall to retrieve later, forget to delete'). However, it does not explicitly state when not to use it, such as for retrieval, which prevents a perfect score.

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