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

Annotations already convey read-only and idempotent behavior, and the description adds useful context such as scoping ('Scoped to your identifier') and the dual-mode behavior (omit key to list). It does not describe error handling or return format, but this is partially covered by the 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 three sentences, front-loaded with the main action, then provides examples, scope, and pairing. Every sentence contributes essential information with no redundancy.

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 read-only tool with strong annotations, the description covers functionality, usage context, scoping, and related tools. Since there is no output schema, not detailing return format is acceptable. The tool is appropriately complete.

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% for the 'key' parameter, so the baseline is 3. The description enriches the parameter meaning by explaining that the key retrieves a value 'previously saved via remember' and that omitting it lists all keys, providing context beyond the schema.

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 clearly states the tool's function with specific verbs and resources: 'Retrieve a value previously saved via remember, or list all saved keys.' It distinguishes itself from siblings by explicitly mentioning remember and forget, and by describing both operational modes.

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 provides explicit when-to-use guidance: 'Use to look up context the agent stored earlier... without re-deriving it from scratch.' It also names alternatives for related operations: 'Pair with remember to save, forget to delete,' effectively delineating when not to use recall.

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