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

Annotations already convey read-only, idempotent, and non-destructive behavior. The description adds valuable behavioral context beyond those: the omit-key listing mode, the scoping of memory to an identifier, and the relationship to remember/forget. It does not describe missing-key or empty-result behavior, but annotations lower the burden.

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 three sentences with no filler. It front-loads the core behavior, then adds use-case context, then scoping and sibling-tool relationships. Every sentence contributes useful 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?

For a simple optional-parameter lookup tool with read-only and idempotent annotations, the description is complete: it covers both invocation modes, gives realistic use examples, explains scoping, and points to related tools. No critical information is missing for an agent to call it 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 fully documents the single optional key parameter, including the omit-to-list behavior, so schema coverage is 100%. The description reinforces this but adds little semantic detail beyond what the schema states, aside from concrete examples of what kind of values are stored.

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 leads with a crisp verb and object combination: 'Retrieve a value previously saved via remember, or list all saved keys.' It also names the sibling memory tools (remember/forget) and distinguishes this tool by its read-only lookup role.

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?

It clearly explains when to use the tool: to look up stored context without recomputing it. It also points to siblings by saying 'Pair with remember to save, forget to delete,' though it stops short of an explicit if-then exclusion like 'do not use for saving.'

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