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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint. The description adds valuable scoping context: 'Scoped to your identifier (anonymous IP, BYO key hash, or account ID).' It also clarifies the listing behavior when key is omitted. This goes beyond annotations, though it doesn't mention edge cases like missing keys or return formats.

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 two sentences, front-loaded with the core function, and every sentence earns its place. It packs purpose, usage, scoping, and sibling relationships without redundancy. No wasted words.

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 and no output schema, the description is complete. It explains what the tool does, when to use it, what data it accesses (saved memories), and how it is scoped. The return behavior is implied by 'Retrieve a value' and 'list all saved keys'. No critical information is missing.

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 description covers the key parameter at 100%, providing a baseline of 3. The tool description adds meaning by giving concrete examples of what keys represent ('the user's target ticker, an address, prior research notes'), enriching the schema's generic 'Memory key' description. This elevates it above baseline.

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 (omit the key argument).' It uses specific verbs (retrieve/list) and identifies the resource (saved values/keys). It also distinguishes from siblings by explicitly mentioning 'Pair with remember to save, forget to delete.'

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?

The description gives explicit when-to-use guidance: 'Use to look up context the agent stored earlier... without re-deriving it from scratch.' It also provides clear alternatives by naming remember and forget. This is strong usage context that helps the agent select the right tool.

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