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

The description goes beyond the annotations by explaining memory scoping ('scoped by your identifier') and persistence details ('Authenticated users get persistent memory; anonymous sessions retain memory for 24 hours'). It also clarifies the relationship with recall and forget, providing a richer behavioral picture.

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 concise yet informative, with four sentences each serving a distinct purpose: action, usage, technical storage detail, and companion tools. It is front-loaded with the primary function and contains no redundant or filler text.

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 (two params, no output schema), the description provides all necessary context: purpose, usage examples, memory scope, persistence behavior, and related tools. Annotations also convey idempotency and non-destructive nature, so the agent has enough information to select and invoke the tool 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?

The input schema already provides 100% coverage with descriptions for both 'key' and 'value'. The description adds examples of content types (ticker, address, preference, research subject) but does not add additional syntax or format details beyond what the schema already specifies, so baseline 3 is appropriate.

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 with a specific verb and resource: 'Save data the agent will need to reuse later.' It also includes examples of what to store and distinguishes itself from sibling tools by explicitly mentioning complementary tools recall and forget.

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 clear when-to-use guidance with concrete examples ('a resolved ticker, a target address, a user preference, a research subject') and mentions complementary tools ('Pair with recall to retrieve later, forget to delete'). However, it does not explicitly state when not to use this tool, so it lacks full exclusion guidance.

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