NEXO Brain

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

No annotations are provided, so the description carries full burden for behavioral disclosure. It only states the action ('Get') without detailing permissions, rate limits, error handling, or whether it's read-only or has side effects. For a tool with no annotations, this minimal description fails to convey key behavioral traits needed for safe invocation.

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 a single, direct sentence with no wasted words, making it highly concise and front-loaded. It efficiently communicates the core action without unnecessary elaboration, though this brevity contributes to gaps in other dimensions.

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?

Given the tool's low complexity (one parameter) and the presence of an output schema (which handles return values), the description is somewhat adequate as a minimal starting point. However, with no annotations and poor parameter documentation, it lacks completeness for safe and informed use, especially compared to richer sibling tools.

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 0% description coverage, with one required parameter 'key' of type string. The description adds no semantic context about what 'key' represents (e.g., format, examples, or valid values), leaving it completely undocumented. With low schema coverage, the description fails to compensate, providing minimal value beyond the bare 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 'Get a specific preference value' clearly states the verb ('Get') and resource ('preference value'), making the basic purpose understandable. However, it doesn't specify what kind of preferences (user, system, application) or distinguish itself from sibling tools like 'nexo_preference_list' or 'nexo_preference_set', leaving the scope vague.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention sibling tools like 'nexo_preference_list' for listing preferences or 'nexo_preference_set' for setting them, nor does it specify prerequisites or contexts for retrieval. This lack of comparative guidance limits effective tool selection.

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