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

Annotations already provide safety hints (idempotent, not destructive, not read-only). The description adds valuable context about persistence (authenticated vs. anonymous sessions) and scoping by identifier. It does not explicitly state overwrite behavior, but idempotentHint implies it, so no contradiction or major gap.

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 four sentences, front-loaded with the core purpose, then usage, then storage details. Each sentence contributes essential information with no redundancy or filler.

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 two-parameter tool with no output schema, the description fully covers purpose, usage, persistence behavior, scoping, and sibling relationships. Nothing important 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?

Schema coverage is 100% with descriptive examples for both 'key' and 'value'. The description adds general usage context but does not explain parameter syntax beyond what the schema already provides. Baseline 3 is appropriate when the schema carries the load.

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 uses a specific verb ('Save data the agent will need to reuse later') and clearly identifies the resource (key-value store scoped by identifier). It distinguishes itself from siblings by explicitly mentioning persistence across conversations/sessions and pairing with recall/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 explicit when-to-use guidance: 'Use when you discover something worth carrying forward' with concrete examples. It also references alternatives by saying 'Pair with recall to retrieve later, forget to delete,' making the usage context clear.

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