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

Annotations already establish readOnlyHint=false and idempotentHint=true. The description adds valuable behavioral context beyond annotations: 'Stored as a key-value pair scoped by your identifier. Authenticated users get persistent memory; anonymous sessions retain memory for 24 hours.' This discloses persistence and scoping details that annotations don't cover, though it doesn't mention overwrite semantics for duplicate keys.

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 only three sentences, front-loaded with the action, and every sentence serves a purpose: the main verb, the use case, and persistence behavior plus sibling tools. No wasted words or redundant information.

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 the tool's simplicity (2 parameters, no output schema), the description fully covers purpose, when to use, persistence semantics, and related tools. It doesn't need to explain return values since a simple confirmation is implicitly expected, and the retention policy addresses the most important contextual concern.

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 clear descriptions for key and value. The description supplements this by providing examples of typical keys (ticker, address, preference) and values (findings, addresses, preferences, notes), which helps the agent infer appropriate parameter usage beyond bare schema definitions.

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 function: 'Save data the agent will need to reuse later' with a specific verb and resource. It distinguishes itself from siblings by explicitly mentioning 'Pair with recall to retrieve later, forget to delete,' making it obvious that remember is for saving while recall and forget handle retrieval and deletion.

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?

Provides explicit when-to-use guidance: 'Use when you discover something worth carrying forward' and gives concrete examples like 'a resolved ticker, a target address, a user preference.' It also names complementary tools (recall, forget), offering clear alternatives for related actions.

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