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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context: the scan is 'symmetric', uses 'the same top-volume universe', and returns 'rule-independent breadth' and '24h liquidity semantics'. The specific caveat that 'a low match count is never reported as breadth' is valuable and prevents misinterpretation of results. No contradiction with annotations.

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 three sentences with no filler: core action and outputs, usage sequence, and an important caveat. It is front-loaded with 'Run one symmetric long/short scan...' and every sentence adds distinct value. Ideal length for the information conveyed.

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?

This is a complex 9-parameter tool with no output schema, and while the description explains the broad output categories and workflow, it does not specify the return format, how breadth vs. candidates are represented, or how parameters like quote/timeframe interact with the scan. It is adequate for initial orientation but not fully complete for a tool of this complexity; the agent would likely need to inspect the schema or call the tool to fully understand the results.

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?

With 56% schema description coverage, the description needed to compensate by explaining parameter intent, but it does not address individual parameters beyond implying longRules/shortRules and universeSize through 'long/short' and 'top-volume universe'. It adds no guidance for quote, lookback, timeframe, limitPerSide, or manualSymbols. The schema descriptions carry the main burden, and the tool description does not enhance parameter understanding meaningfully.

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 states a specific verb and resource: 'Run one symmetric long/short scan over the same top-volume universe' and enumerates concrete outputs ('rule-independent breadth, 24h liquidity semantics and ranked directional candidates'). It also distinguishes itself from downstream analysis tools by positioning itself as the first pass before deep-dive with derivatives/order-flow tools. This is far more specific than a generic 'scan' and leaves little ambiguity about what the tool does.

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 guidance: 'Use this first for comprehensive day-trade or scalp discovery; then deep-dive only the shortlist with derivatives/order-flow tools.' This clearly tells the agent when to invoke this tool and what to do next. However, it references tool categories rather than specific sibling names like 'screener_run' or 'orderflow_read', so the routing is clear but not as precise as naming exact alternatives.

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