list_universes

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

With no annotations provided, the description carries the full burden of disclosing behavior. It states the tool lists universes and sizes, implying a read-only operation, and adds the detail 'bundled' to indicate these are pre-defined sets. However, it does not explicitly state whether side effects or restrictions apply, though for a simple list this is minimal. The description is adequate but not rich in behavioral disclosure.

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, concise sentence that front-loads the action and resource, with no redundant information. Every word contributes to meaning ('bundled', 'stock ticker universes', 'sizes').

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 zero-parameter list tool, the description is largely sufficient. It clearly states what the tool returns (universes and sizes) and an output schema exists to document the return structure. There is no missing contextual information that would confuse an agent. A minor gap is the lack of explanation for what 'bundled' means, but that is not critical for invocation.

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 tool has zero parameters, so no parameter explanations are needed. The schema coverage is effectively 100% (empty properties), and the description adds relevant context about the output (universes and sizes). Per rubric, zero parameters warrants a baseline of 4.

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 primary action ('List') and the specific resource ('bundled stock ticker universes') plus the additional detail 'and their sizes'. This distinguishes it from sibling tools like list_strategies (which lists strategies) and get_price/get_prices (which fetch price data).

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 implies when to use the tool (when you need to know available stock ticker universes and their sizes) but provides no explicit when-to-use or alternative guidance. There are no direct alternatives among siblings, so the usage is straightforward, but the lack of explicit context keeps it at a baseline level.

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