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

The readOnlyHint annotation already signals the tool is safe and read-only. The description adds the behavioral nuance that only symbols with cached live data are returned, which is useful context beyond the annotation. However, it does not disclose rate limits, response format, or other behaviors, so it stays at a baseline 3.

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 two sentences with no unnecessary words. The first sentence states the core function, and the second elaborates with practical use cases. It is front-loaded and directly actionable, earning a top score.

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?

The tool is simple (one optional parameter, no output schema). The description clearly communicates what the tool returns (a list of symbols) and when to use it, making it complete for the agent to understand purpose and invocation. The readOnlyHint annotation further covers safety, so no additional context is required.

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 schema provides 100% description coverage for the single apiKey parameter, so the description does not need to add parameter-level detail. It adds no extra semantics, but the schema already fully compensates, keeping the score at the baseline 3.

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 ('List') and identifies the resource ('symbols currently queried with live data cached'), which clearly distinguishes it from sibling tools like get_tickers or get_universe that likely return broader symbol sets. It also enumerates concrete use cases (checking if a ticker has been warmed up, enumerating live tracking), making the purpose unambiguous.

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 clear context on when to use the tool: to view active real-time symbols, check warm-up status, or enumerate tracked symbols. It does not explicitly name alternatives or state when not to use it, but the use cases imply its scope, earning a 4 rather than a 5.

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