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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds useful context: scoping to the agent's identifier, the list-all-behavior when key is omitted, and the pairing with remember/forget. It stops short of documenting missing-key behavior or broader access-control details, but the annotation coverage lowers 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?

Three purposeful sentences, front-loaded with the core operation, followed by use case, scope, and related-tool references. Every sentence earns its place with no filler.

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?

The tool has one optional parameter, full schema coverage, and strong annotations. The description covers purpose, use case, scope, and sibling relationships, providing an agent everything needed 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?

Schema coverage is 100%, and the description's parameter guidance ('omit the key argument to list all saved keys') mirrors the property description exactly. The description adds no new parameter-level semantics beyond what the schema already documents, so the baseline of 3 applies.

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: 'Retrieve a value previously saved via remember, or list all saved keys.' This clearly distinguishes the tool from siblings like remember and forget, and identifies both primary modes of operation.

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 the tool: 'Use to look up context the agent stored earlier' and contrasts it with 'without re-deriving it from scratch.' It also names sibling tools as alternatives: 'Pair with remember to save, forget to delete.'

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