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

Beyond the annotations, the description reveals that memory is 'scoped by your identifier,' that authenticated users get persistent memory, and that anonymous sessions retain memory for 24 hours. This adds meaningful behavioral context about persistence and visibility that annotations alone don't provide.

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 five sentences but each is purposeful: it states the purpose, offers usage examples, explains scoping/persistence, and names companion tools. It is front-loaded with the core function.

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 save tool, the description covers persistence behavior, TTL, scoping, and integration with recall/forget. No output schema exists, but return values are trivial for a save operation, so nothing meaningful 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 description coverage is 100%, with both 'key' and 'value' already described in the input schema. The description only adds a high-level 'key-value pair' framing, which adds little 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 uses a specific verb ('Save') and resource ('data the agent will need to reuse later'), clearly stating the tool's function. It explicitly frames persistence across conversations/sessions and distinguishes itself from sibling tools by referencing 'Pair with recall to retrieve later, 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 with concrete examples ('a resolved ticker, a target address, a user preference'). It names companion tools (recall, forget) but does not provide an explicit when-not-to-use scenario, so it falls short of the full 5.

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