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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false. The description adds meaningful behavioral context beyond this: it specifies 'No input required — GET,' and details the exact return payload (per-signal phase angles, resonance clusters, amplification factor, system resonance score, historical comparison). This goes beyond the minimal annotation 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?

The description is dense and front-loaded with the core purpose, then elaborates with a vivid analogy and a clear enumeration of outputs. While slightly long, every sentence contributes functional or contextual information, and the structure flows logically from purpose to behavior to output. The final GET note is economical.

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 the tool has no parameters and a rich output schema, the description is fully complete: it explains the conceptual trigger, the signal scope (28 signals, 5 domains), the amplification concept, the exact return fields, and the historical comparison references. The description leaves no material questions about when or how to invoke the tool.

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 the baseline is 4. The description reinforces this with 'No input required — GET,' leaving no ambiguity about invocation. There is no schema-level parameter detail to compensate for, and the description adds sufficient clarity for a parameterless tool.

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 opens with a specific verb-resource pair: 'detects when multiple independent macro forces are oscillating in phase,' clearly identifying what the tool does. It further distinguishes itself by contrasting a single shock with resonance and explicitly listing the output categories, making it distinct from sibling tools like intelligence.contagion or intelligence.aftershock.

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 usage for detecting systemic resonance ('detects when multiple independent macro forces are oscillating in phase'), and the phrase 'A single shock is manageable; resonance turns a bad quarter into a systemic crisis' gives conceptual context. However, it does not explicitly state when to use this tool over alternatives or mention any exclusions, leaving the comparative guidance to inference.

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