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

The description adds meaningful behavioral context beyond annotations: data is scoped by identifier, and retention varies (persistent for authenticated users, 24h for anonymous). It also explains the memory lifecycle by referencing recall and forget. Annotations already indicate non-read-only and idempotent, so the bar is lower; the description covers key additional traits. It doesn't mention overwrite behavior, but this is minor given the idempotent hint.

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 composed of four concise sentences that front-load the core purpose, then provide usage cues and lifetime details. Every sentence adds value and there is no fluff or redundancy.

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 ample annotations and no output schema, the description is complete. It covers purpose, usage, scoping, persistence, and companion tools, giving the agent all necessary context to use the tool effectively.

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% and parameters are well-described. The description adds context about key-value storage and scoping, but doesn't add substantial syntax or format details 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 clearly states the tool's purpose: 'Save data the agent will need to reuse later.' It explicitly identifies the resource (key-value storage) and distinguishes itself from sibling tools by noting 'Pair with recall to retrieve later, forget to delete.' This differentiates it from the memory retrieval and deletion tools.

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: 'Use when you discover something worth carrying forward (a resolved ticker, a target address, a user preference, a research subject)'. It also clarifies persistence conditions (authenticated vs. anonymous) and mentions companion tools (recall, forget), giving the agent a clear decision framework.

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