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

The description discloses methodology (z-scored history since FY1981), update frequency (monthly), and the Gold-tier requirement for the `days` parameter (the description explicitly states that without Gold tier, the current snapshot is returned). This adds value beyond the readOnlyHint annotation, which already signals a safe read operation.

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 long, front-loaded with the core purpose, followed by when-to-use guidance and update frequency. Every sentence carries useful information without 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?

Despite having no output schema, the description enumerates the return fields (stress_score, revenue_trend, spending_trend, historical_percentile, confidence, methodology_version). It also explains the scoring basis, update cadence, and parameter behavior, making the tool well-suited for an agent to decide and invoke correctly.

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 description covers the `days` parameter fully (optional, returns history, requires Gold tier, falls back to snapshot). The tool description does not add any extra parameter-specific meaning beyond what the schema already provides. With 100% schema coverage, the baseline of 3 is appropriate.

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 ('Returns a 0-100 US federal budget deficit stress score') and clearly states the resource and methodology (monthly federal receipts vs. outlays, z-scored against 45.8 years of history). It also lists the exact output fields, making the tool's purpose unambiguous and distinct from the many sibling tools.

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?

Provides explicit trigger conditions: 'Call when the user asks about the federal deficit, fiscal stress, tax-revenue erosion, Treasury borrowing needs, or shutdown risk, or when timing duration, auction-supply, or government-contract exposure decisions.' This gives clear guidance on when to invoke this tool, though it doesn't mention alternative tools by name.

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