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

The annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context beyond that: scoping by user identifier, persistence differences between authenticated users and anonymous sessions, and the ability to delete via 'forget'. This exceeds what annotations alone convey.

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 well-structured and front-loaded, opening with the core purpose and then providing usage triggers, storage details, and companion tools. Every sentence adds value, with no redundancy or filler. Despite being moderately long, it remains concise given the information covered.

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 key-value store with two required parameters and no output schema, the description is complete. It explains the tool's purpose, when to use it, storage model, persistence scoping, and related tools. No critical information is missing for an agent to select and invoke it correctly.

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% for both parameters, so a baseline of 3 applies. The description adds meaningful examples beyond the schema by illustrating typical keys ('a resolved ticker, a target address, a user preference') and value types ('findings, addresses, preferences, notes'), enriching parameter understanding without replacing schema details.

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 clearly states the tool's purpose with a specific verb ('Save') and resource ('data the agent will need to reuse later'). It distinguishes from siblings by explicitly naming 'recall' and 'forget' as companion tools, making the tool's role in the memory workflow clear.

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 use cases ('Use when you discover something worth carrying forward') with concrete examples (resolved ticker, target address, user preference, research subject). It also names alternatives/companion tools ('Pair with recall to retrieve later, forget to delete'), satisfying the highest bar for usage guidance.

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