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

The description discloses storage mechanics beyond the annotations: key-value pair scoped by agent identifier, persistence differences between authenticated and anonymous sessions (24 hours), and relationship to related tools. Annotations only indicate idempotent, non-destructive, and non-read-only, so the description adds significant behavioral context.

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, front-loaded with the core purpose. The middle sentence provides concrete use cases, and the final sentence covers storage mechanics and persistence. Every sentence contributes critical guidance with no 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 tool with two parameters, no output schema, and clear annotations, this description is complete. It covers what, when, why, and how, plus integration with recall and forget. No missing information or ambiguity remains.

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?

The schema already fully describes both parameters (key, value) with examples. The description adds the semantic nuance that the pair is 'scoped by your identifier,' clarifying that keys are not global and are tied to the caller, which is not present in the schema.

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 specific action ('Save data the agent will need to reuse later') with a clear resource (data keyed by identifier). It distinguishes from sibling tools by explicitly telling the user to 'Pair with recall to retrieve later, forget to delete.'

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 gives explicit when-to-use guidance: 'Use when you discover something worth carrying forward' with concrete examples (ticker, address, preference). It also names the companion tools (recall, forget), providing context on the lifecycle and alternatives.

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