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

Beyond the annotations (idempotent=true, destructive=false), the description adds valuable behavioral context: key-value scoping by identifier, persistent memory for authenticated users, and 24-hour retention for anonymous sessions. These details are not present in the annotations and meaningfully inform agent expectations.

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 concise sentences, each earning its place: purpose, usage scenarios, scoping/persistence, and pairing with related tools. It is front-loaded with the core action and contains no redundant or filler text.

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 2-parameter write tool with no output schema, the description covers all essential aspects: what it does, when to use it, how data is scoped, retention semantics, and how it relates to recall/forget. It is fully self-contained and complete.

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 description coverage is 100%, with both `key` and `value` having detailed descriptions and examples. The tool description reinforces the kind of content to store (ticker, address, preference) but does not add parameter-specific information beyond what the schema already provides. 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 states the tool's purpose with a specific verb and resource: 'Save data the agent will need to reuse later'. It clearly distinguishes from sibling tools by explicitly pairing with 'recall' and 'forget' for retrieval and deletion, respectively.

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 provides concrete when-to-use scenarios ('when you discover something worth carrying forward... so you don't have to look it up again') and names the alternatives ('Pair with recall to retrieve later, forget to delete'). This gives clear usage guidance relative to sibling memory tools.

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