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

Annotations already indicate idempotent and non-destructive, but the description adds meaningful context: key-value scoping by identifier, persistence differences between authenticated and anonymous sessions (24-hour retention), and the storage model. These details go beyond annotations and help the agent anticipate behavior accurately.

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 four sentences long, front-loaded with the core purpose, and every sentence provides value: when to use, storage details, and pairing. No filler or repetition.

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 tool with no output schema, the description covers purpose, usage, behavior, and pairing. It is complete and self-contained, giving the agent everything needed to decide when and how to use it.

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 clear parameter descriptions and examples. The description reinforces the key-value relationship and adds scoping context, which slightly exceeds the baseline. It doesn't add syntax details beyond the schema, but the key-value framing is helpful.

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: saving data for later reuse across conversations or sessions. It uses the specific verb 'save' and names the resource (data/notes), and it distinguishes itself from sibling tools by explicitly mentioning recall and forget as complementary actions.

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?

Provides explicit when-to-use guidance ('when you discover something worth carrying forward') and names the alternatives ('Pair with recall to retrieve later, forget to delete'). This clearly separates it from reading or deletion tools and gives the agent a decision rule.

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