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

Annotations already establish readOnly and idempotent safety. The description adds value by disclosing scoping behavior ('Scoped to your identifier...') and the two modes of operation (regular retrieval vs. listing all keys). It doesn't cover missing-key behavior, but that minor gap is offset by annotation coverage.

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 four tightly written sentences, each contributing essential information: main function, use case, scoping, and pairing with sibling tools. No filler or 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 tool with one optional parameter and no output schema, this description is nearly complete. It covers purpose, usage context, scoping, and sibling relationships. The only missing detail is what happens when a key doesn't exist, but this is a minor omission given the simplicity of the tool.

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 parameter description already states 'omit to list all keys'. The description reinforces this with practical examples of what keys represent ('target ticker, an address, prior research notes'), but does not add novel parameter semantics beyond the schema. Baseline 3 is appropriate.

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.' It clearly distinguishes from siblings by naming remember and forget as the counterpart operations, and provides concrete examples (user's target ticker, address, prior research notes).

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... without re-deriving it from scratch.' It also names how to pair it with remember (save) and forget (delete), which are direct alternatives.

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