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

Annotations already indicate idempotentHint=true, destructiveHint=false, and readOnlyHint=false, which covers basic safety. The description adds meaningful behavioral context beyond those flags: persistence across sessions, 24-hour retention for anonymous sessions, and scoping by identifier. It does not contradict the annotations, though it could have explicitly stated overwrite behavior for existing keys; however idempotentHint implies a safe, repeatable write.

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 with no filler. It front-loads the action ('Save data...'), then provides when-to-use, storage model, and related tools. Every sentence carries useful information, and the use-case examples are concise but illustrative.

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 write tool with full schema coverage and no output schema required, the description is complete. It covers what the tool does, when to use it, how storage works (key-value, identifier-scoped), persistence details, and companion tools. There are no significant gaps for an agent to invoke it 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%, so the baseline is 3. The description adds extra semantics by framing the pair as 'scoped by your identifier' and giving example use cases (ticker, address, preference) that map to the key/value purpose. The schema already provides key and value descriptions and examples, so the description reinforces rather than significantly expands parameter meaning, but the scoping detail is a genuine enhancement.

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 opens with 'Save data the agent will need to reuse later — across this conversation or across sessions,' which is a specific verb-plus-resource statement that clearly defines the tool's scope and purpose. It also distinguishes this tool from its siblings by explicitly pairing it with recall and forget, making it evident that remember is for storing, not retrieving or deleting.

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: 'Use when you discover something worth carrying forward (a resolved ticker, a target address, a user preference, a research subject) so you don't have to look it up again.' It gives concrete trigger examples and explains the benefit. It also refers to complementary tools ('Pair with recall to retrieve later, forget to delete'), helping the agent choose the right tool.

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