market-overview

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

No annotations are provided, so the description bears full responsibility. It discloses data source (Yahoo Finance) and freshness (live during market hours), which are helpful. However, it does not describe behavior outside market hours (e.g., stale data), error conditions, or response format details. It mentions a 'structured payload' but not its structure. A score of 3 reflects adequate but not exhaustive transparency.

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 extremely concise: two sentences pack all essential information—tool purpose, included data, use cases, and data source. Every word earns its place; no redundancy or fluff.

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 zero parameters and no output schema, the description is largely self-contained. It covers returned data, use cases, source, and freshness. It does not explain the risk-posture signal algorithm or potential empty responses, but for a simple snapshot tool this is minor. A score of 4 reflects its adequacy for most use cases.

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?

There are zero parameters, and schema coverage is trivially 100%. The description adds value by explaining what the tool returns without needing inputs, listing the exact data points. For a no-parameter tool, this is strong semantic context 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 clearly states it provides a market snapshot with specific indices (SPY, QQQ, IWM, DIA) and metrics (price, % change, VIX, yield, risk signal). It explicitly distinguishes itself by claiming to replace 5-6 individual price calls with a single call, making it distinct from sibling tools like stock-brief or equity-brief.

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 clear use cases: position-sizing, regime detection, pre-trade context. It implies when to use this tool over individual calls by stating it replaces them. However, it does not explicitly exclude scenarios where more detailed data (e.g., from a single stock's brief) would be better, but the provided context is sufficient for most agents.

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