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

The description's core action ('Delete') aligns with the annotations destructiveHint=true and idempotentHint=true. It does not contradict them. However, it adds little behavioral detail beyond what the annotations already disclose—it does not explain what happens if the key doesn't exist, whether deletion is permanent, or any side effects. Since annotations cover the safety profile, the description's marginal contribution is limited.

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: the first states the action and target, the second gives usage guidance and complementary tools. No filler, no 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 simple one-parameter delete tool with full schema and annotations, the description is sufficient. It provides usage context (when to delete) and pairing advice. The lack of an output schema is acceptable because the operation is straightforward, though the description does not state what happens after deletion (e.g., confirmation or error handling), which would make it truly complete.

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 input schema has complete coverage (100%) for the only parameter `key`. The description merely states 'by key' without additional meaning. With full schema coverage, the baseline is 3; it adds no further semantic detail.

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 ('Delete') and a clear resource ('previously stored memory') and explicitly states the operation is by 'key'. This directly distinguishes the tool from siblings like remember and recall, which are mentioned for context.

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 explicitly states when to use ('context is stale', 'task is done', 'clear sensitive data') and mentions alternative/complementary tools ('Pair with remember and recall'). This gives concrete usage guidance beyond what the schema provides.

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