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

Adds key behavioral context beyond annotations: scoping by identifier, persistence differences between authenticated (permanent) and anonymous (24-hour) sessions. Annotations declare idempotentHint=true, which aligns with the description's implication that overwriting the same key replaces value. No contradictions.

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?

Extremely concise: 4 sentences covering purpose, usage context, behavioral details, and companion tools. No filler, every sentence adds value. Front-loaded with the 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 simple write tool with no output schema and only two required parameters, the description covers all necessary context: data type, scope, persistence, and integration with related tools. Complete and self-contained.

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%, so the description provides limited added parameter meaning beyond schemas. It gives examples of possible values for the 'value' parameter (findings, addresses, etc.), which is helpful but not substantial. Baseline of 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?

Description clearly states the tool saves data for later reuse, specifying key-value pairs and scoping. It distinguishes from siblings 'recall' and 'forget' by directly mentioning them as companions. The verb 'save' and resource 'data' are specific and actionable.

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 states when to use: 'when you discover something worth carrying forward' with concrete examples (ticker, address, preference). Mentions pairing with recall and forget. Lacks explicit when-not-to-use or comparison to alternative tools beyond these siblings, but sufficient for practical guidance.

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