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

No annotations are provided, so the description carries the behavioral burden. It discloses the data-delay behavior (free tier: one market day delayed), the fallback behavior for unknown symbols (returns valid-symbol directory), and the fact that every name carries coil fields. It could add rates/limits, but for a read tool this is strong coverage.

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?

Four dense sentences with a clear front-loaded summary of what the tool returns. Every sentence adds information: output fields, accepted universe, unknown-symbol behavior, free tier caveat, and sibling routing. No filler.

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 single-parameter read tool with no output schema, this description is fully sufficient. The agent knows the input format, expected output content, error behavior, data freshness, and when to choose the live alternative. A higher score is not needed because the parameter count is minimal and the behavior is completely covered.

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 documents only one parameter (symbol) with an example, so the description does not need to repeat syntax. It adds useful semantic context beyond the schema by telling the agent which symbol universe is accepted and what happens for unknown symbols.

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+resource ('One stock's full Coil read') and enumerates the exact data fields delivered: opportunity 0-100, board percentile, entry quality/state, hold strength, leadership flag, and book regime. It also differentiates from the live sibling by naming get_stock_read_live explicitly.

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 scope ('Any S&P 500, Nasdaq-100 or macro name'), explains the free-tier delay, and routes to the paid live sibling when real-time data is required. It also tells the agent what happens for unknown symbols, which removes a likely error path.

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