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

Annotations indicate idempotentHint=true and destructiveHint=false. The description adds critical behavioral details: scoped by identifier, persistent memory for authenticated users, 24-hour retention for anonymous sessions. It also explains how it pairs 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?

The description is tightly written in three sentences with no extraneous text. It front-loads the core purpose and then efficiently adds context (scoping, retention, pairing) without 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 tool with 2 required parameters and no output schema, the description covers all necessary aspects: purpose, usage scenarios, behavioral traits, and how it integrates with sibling tools. No gaps are apparent.

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% with descriptions for both parameters. The description reinforces this with usage examples ('subject_property', 'target_ticker') and context, adding meaning beyond the schema alone. While the schema already covers format, the description's examples enhance semantic understanding.

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 verb-resource pair ('Save data...to reuse later') and clearly defines the tool's function as storing key-value pairs. It distinguishes from siblings by naming recall and forget as complements, making the purpose unambiguous.

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 provides explicit when-to-use guidance ('when you discover something worth carrying forward') with concrete examples. It suggests pairing with recall and forget but does not explicitly state when not to use the tool. This is a minor gap, but the context is clear enough.

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