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

Annotations only indicate idempotentHint=true, destructiveHint=false, and readOnlyHint=false. The description adds valuable behavioral context beyond these hints: storage as a key-value pair scoped by identifier, persistent vs 24-hour TTL based on auth status, and the lifecycle with recall and forget. No contradictions with 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?

The description is well-structured: it opens with purpose, gives usage context, then details scoping and persistence, and ends with sibling relationships. Every sentence adds information and there is no redundancy or fluff. It is appropriately sized for a simple tool.

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 save tool, the description covers all relevant aspects: storage model, scoping, TTL, authentication differences, and how it links to recall/forget. No output schema is present, but the description makes clear the saved data is not returned and must be retrieved via recall. The tool is fully understood from the description.

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 both key and value having descriptive names and examples. The description reinforces the key-value concept and gives examples, but it does not add meaning beyond what the schema already provides. Baseline 3 is appropriate because the schema carries the semantic weight.

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 opens with a specific verb and resource: 'Save data the agent will need to reuse later.' It clearly distinguishes the tool from siblings by explicitly pairing it with 'recall' to retrieve and 'forget' to delete, and provides concrete use-case examples like 'resolved ticker' and 'user preference.'

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 states when to use the tool ('Use when you discover something worth carrying forward') and gives examples of appropriate content. It also names alternatives ('Pair with recall to retrieve later, forget to delete') and explains persistence differences for authenticated vs anonymous sessions, giving the agent clear decision criteria.

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