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

The annotation already declares non-readonly and non-destructive behavior, and the description goes further by explaining the key-value store is scoped by user identifier and noting persistence differences ('Authenticated users get persistent memory; anonymous sessions retain memory for 24 hours'). This adds meaningful lifecycle context beyond the annotations. No contradiction with annotations.

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?

Three sentences, each with a distinct job: statement of purpose, usage guidance, and storage/behavior details. It is front-loaded and avoids fluff.

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 annotations, the description covers purpose, usage, storage semantics, persistence, and complementary tools. There is no output schema, but return values are not essential to understanding this tool.

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?

With 100% schema coverage, the description rests on solid schema descriptions. It reinforces the key-value pair concept and gives examples ('subject_property', 'target_ticker') that align with the two parameters, but adds little technical detail beyond the schema. This meets the baseline for covered schemas.

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 a specific action ('Save data') and a clear resource ('data the agent will need to reuse later'), then distinguishes itself from siblings by explicitly naming recall (retrieve) and forget (delete) as complementary operations. This makes the tool's role in the memory lifecycle unmistakable.

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 explicitly states when to use it ('Use when you discover something worth carrying forward') and gives concrete examples (resolved ticker, target address, user preference). It also points to alternatives ('Pair with recall to retrieve later, forget to delete'), satisfying the 'when/alternatives' criterion.

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