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

Discloses storage as key-value pairs scoped by identifier, persistent for authenticated users vs. 24-hour retention for anonymous sessions. Adds value beyond annotations by clarifying lifecycle and access boundaries.

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 focused sentences: purpose first, usage scenario, behavior details, and pairing tools. No fluff 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?

Given only two required string params and no output schema, the description fully covers storage semantics, scope, pairing with recall/forget, and retention policy.

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 describes both parameters (key and value) with 100% coverage. The description adds practical naming examples and clarifies that value can be any text, providing slight additional context.

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?

Description starts with a clear verb-resource combination ('Save data the agent will need to reuse later') and immediately distinguishes itself from siblings ('recall', 'forget') by specifying its role as storage.

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?

Explicitly states when to use ('when you discover something worth carrying forward') and pairs with recall/forget for retrieval and deletion, providing clear decision context.

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