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

Annotations already establish safety (readOnlyHint=true, destructiveHint=false). The description adds valuable context about scoping ('Scoped to your identifier') and the omit-key-to-list behavior, enriching the agent's understanding without contradicting 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?

Three sentences front-load the core action, then provide use case, scoping, and companion tools. Every sentence earns its place with no filler, making it both concise and structured.

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 tool with one optional parameter, complete schema coverage, and strong safety annotations, the description covers purpose, usage, and scoping thoroughly. The only gap is unspecified behavior for missing keys, which is not critical for tool selection or invocation.

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 property description already explains 'Memory key to retrieve (omit to list all keys)'. The description's key-related text mirrors this, adding no new semantic meaning beyond what the schema provides.

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?

Uses specific verbs 'Retrieve' and 'list' with a clear resource ('value previously saved via remember'). Explicitly distinguishes itself from sibling tools by tying functionality to the remember/forget memory system, making it unmistakable which tool this is.

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?

Provides an explicit use case: 'look up context the agent stored earlier... without re-deriving it from scratch' and names companion tools (remember, forget). However, it does not explicitly state when not to use the tool or offer alternative tools, so it falls short of a 5.

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