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

Annotations already provide readOnlyHint=false, idempotentHint=true, destructiveHint=false. The description adds valuable context beyond annotations: key-value scoping by identifier, persistence differences (authenticated vs anonymous), and the fact that it's a write operation. No contradictions.

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 three sentences, each serving a distinct purpose: purpose, usage guidance, behavioral context. Every sentence is informative, no fluff, and the most critical info is front-loaded.

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 that there is no output schema, the description adequately explains the storage mechanism, scoping, and retrieval pairing. Combined with rich annotations and clear parameter schema, the tool's behavior is fully specified for effective agent use.

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 'key' and 'value'. The description adds naming convention examples for keys and specifies that values can be any text, which slightly enhances meaning beyond the schema. A higher score would require more detailed format specifications.

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 uses a specific verb 'Save data the agent will need to reuse later' and clearly indicates the resource (key-value memory). It distinguishes from sibling tools 'recall' and 'forget', 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 explicitly states when to use: 'when you discover something worth carrying forward' and provides examples. It also mentions pairing with 'recall' and 'forget' for completeness and gives storage scoping details, leaving no ambiguity about alternatives.

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