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

The description adds meaningful behavior beyond annotations: storage is a key-value pair scoped by the agent identifier, authenticated users get persistent memory, anonymous sessions expire after 24 hours, and recall/forget are the companion tools. No contradiction with the readOnlyHint/idempotentHint 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?

The description is tightly written and front-loaded with the core purpose. Each sentence adds useful information: when to use, how storage works, persistence behavior, and companion tools. There is 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 write tool with no output schema, the description is complete. It covers purpose, usage triggers, storage semantics, retention behavior, and sibling tool routing. No critical information needed for correct invocation is missing.

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%, so the baseline is 3. The description reinforces the key/value model and gives examples that closely mirror the schema descriptions, but it does not add significant per-parameter meaning beyond what the schema already provides.

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 a clear verb and resource: 'Save data the agent will need to reuse later,' with concrete example content (ticker, address, preference, research subject). It also distinguishes the tool from its siblings by framing it as the write side of a memory pair with recall and forget.

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 gives explicit when-to-use guidance: 'Use when you discover something worth carrying forward,' with concrete examples. It does not state when not to use the tool or explicitly compare to alternative memory tools beyond naming recall and forget, so it stops short of a full 5.

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