Remember

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

Discloses persistence and encryption ('persistent encrypted memory sealed client-side'), adding value beyond annotations. Also mentions update behavior. No contradiction with annotations (readOnlyHint=false, destructiveHint=false).

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?

Two concise sentences; purpose is front-loaded, and every word adds value. No redundancy or filler.

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 output schema exists (as per context), description need not explain return values. It covers creation/update behavior adequately. Could mention error handling but not critical for a simple tool.

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 provides full parameter descriptions, and description adds context about encryption and persistence. The description clarifies the purpose of the cellId parameter for updates, complementing 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?

Clearly states verb (store), resource (information to persistent encrypted memory), and distinguishes from siblings (for persisting facts across sessions). Also mentions update capability, 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?

Explicitly tells when to use (when a fact, decision, or context needs persistence across sessions). Does not explicitly state exclusions, but sibling context allows inference of alternatives like saihm_recall or saihm_forget.

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