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

Goes beyond annotations by detailing storage as key-value pair scoped by identifier, persistence differences for authenticated vs anonymous users (24-hour retention), and pairing with recall/forget. No contradictions 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?

Four sentences, front-loaded with main purpose, followed by usage guidance and behavioral details. Every sentence adds value; no redundant or extraneous information.

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?

Given two simple parameters, no output schema, and annotations, the description is complete. It explains scope, persistence, and how to use with sibling tools, covering all necessary context for an agent.

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 already provides clear descriptions for key and value. The tool description adds context about usage but does not elaborate on parameter specifics beyond what schema offers. Baseline 3 is appropriate given full schema coverage.

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 action ('save'), the resource ('data the agent will need to reuse later'), and the scope ('across this conversation or across sessions'). It distinguishes from sibling tools like recall and forget by explicitly naming them as companions.

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 guidance on when to use: 'when you discover something worth carrying forward' with concrete examples. Does not explicitly state when not to use, but implies alternatives via mention of recall and forget.

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