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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description adds valuable context beyond those: scoping to the agent's identifier and the dual behavior of retrieving vs listing. No contradiction with annotations, though it doesn't disclose return format or error behavior, which are minor for this simple read operation.

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-loaded with the action, and every sentence earns its place. Examples are illustrative without being verbose; 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, no output schema, and strong annotations, the description covers purpose, usage context, scoping, and relationship to sibling tools. Nothing essential is missing for an agent to correctly select and invoke it.

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 schema already describes the 'key' parameter, including the 'omit to list all' behavior. The description restates this but adds no new parameter-level semantics, so the baseline of 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 ('Retrieve') and resource ('value previously saved via remember'), and explicitly distinguishes the listing behavior ('or list all saved keys'). It differentiates from sibling tools by naming remember and forget, making clear this is the retrieval counterpart.

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 explicit when-to-use guidance: 'Use to look up context the agent stored earlier' with concrete examples (ticker, address, notes). It also names the paired operations ('Pair with remember to save, forget to delete') and explains the alternative of omitting the key to list all keys.

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