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

Annotations provide idempotentHint true and destructiveHint false. Description adds valuable behavioral details: key-value scoped by identifier, persistence differences between authenticated (persistent) and anonymous (24-hour), and pairing with recall/forget. No contradiction, and value is added beyond annotations.

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?

Description is concise with no wasted words. Each sentence serves a purpose: stating function, usage context, technical detail (scoping, persistence), and pairing with other tools. Front-loaded with primary purpose.

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 tool with only two simple string parameters and no output schema, the description is exceptionally complete. It covers what the tool does, when to use it, how it behaves (persistence, scoping), and how it relates to sibling tools (recall, forget). No gaps.

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 has 100% coverage with descriptions for both 'key' and 'value'. Description reinforces key-value pair concept and provides example key patterns (e.g., 'subject_property', 'target_ticker'), adding practical context beyond schema. Baseline 3 is appropriate, plus extra for examples.

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?

Description clearly states the tool saves data for reuse across conversations or sessions, with specific verb 'save' and resource 'data'. It distinguishes from sibling tools 'recall' and 'forget' by describing pairing. Examples (resolved ticker, target address, etc.) further clarify purpose.

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?

Description explicitly says 'Use when you discover something worth carrying forward' and gives concrete examples. It implies when to use but does not explicitly state when not to use; however, the context is clear and alternatives (recall/forget) are mentioned.

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