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

Annotations already declare readOnly/indempotent/non-destructive. Description adds scoping to identifiers and the behavior of omitting key (list all). No contradiction.

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?

Two concise sentences: first states core function, second provides usage guidance and pairings. Front-loaded with key action, no redundant 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 single-parameter tool without output schema, the description covers purpose, usage scenarios, scoping, and sibling relationships completely.

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% with description for 'key' property. The overall description adds meaning by explaining the effect of omitting the argument and providing real-world examples, going beyond schema documentation.

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 verb ('Retrieve') and resource (values saved via remember), and distinguishes between two behaviors (value retrieval vs. listing keys). It also separates from sibling tools by mentioning remember and forget.

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 clear context on when to use (look up stored context, avoid re-derivation) and mentions scoping. Implicitly tells when not to use (when saving or deleting), but lacks explicit exclusion or alternative naming.

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