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

Annotations already declare read-only, idempotent, and non-destructive behavior. The description adds valuable behavioral context: the tool is scoped to an identifier (anonymous IP, BYO key hash, or account ID), and it supports two distinct modes (retrieve vs. list). This goes beyond the annotations without contradicting them.

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 long, front-loaded with the core action, and every sentence earns its place: the first states the dual functionality, the second gives usage context, and the third explains scoping and companion tools. No unnecessary words or repetition.

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 a single optional parameter, no output schema, and strong annotations, the description covers all essential aspects: purpose, usage context, scoping, and relationship to related tools. It adequately informs the agent about what the tool does and when to use it, making it complete for this level of complexity.

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?

The schema provides a description for the 'key' parameter (omit to list all keys), giving 100% coverage. The description reinforces this and adds further meaning: the key was previously saved via 'remember', and gives practical examples of what the value might hold, such as a target ticker or address. This enriches the parameter semantics 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: retrieve a value previously saved via remember, or list all saved keys. It specifies the resource (memory) and the verb (retrieve/list), and distinguishes it from sibling tools 'remember' and 'forget' by explicitly pairing with them.

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 explicitly states when to use: 'Use to look up context the agent stored earlier — the user's target ticker, an address, prior research notes — without re-deriving it from scratch.' It also names the complementary tools 'remember' and 'forget' and clarifies the scoping behavior, providing clear context for when this tool is appropriate.

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