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

The annotations already declare readOnlyHint=true, so the description need not repeat safety info. It adds useful context: 'Updates: quarterly' and reveals the scoring methodology (YoY debt growth adjusted for interest rate trend). It also lists output fields, giving a clear behavioral picture without contradicting 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 packed with information in two sentences: what it returns, the fields, and when to use it. It is front-loaded with the primary output. Though it is a dense single sentence, every part is relevant and there is no waste.

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 simple read-only tool with one optional parameter, the description covers the main return fields, the score's meaning, and appropriate use cases. It lacks an output schema, but the description lists the fields and history. The only minor gap is not explaining the interaction between the default snapshot and the 'days' parameter, but the schema covers that.

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 covers the only parameter 'days' with a full description, meeting 100% schema coverage. The tool description adds no parameter information, but the schema does the heavy lifting, so a baseline score 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 clearly states the tool returns a specific 0-100 fiscal-stress score, lists the exact fields included (total_debt, debt_yoy, change_30d, interest_rate_trend, 12-month history), and explains the formula. It is precise about the resource (US Treasury fiscal stress) and the action (returns a score), making it unambiguous and distinct from generic siblings.

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 explicitly tells when to use it: 'Call when the user asks about federal debt growth, fiscal sustainability, deficits, or the US interest burden...' This is strong when-to-use guidance. However, it does not mention alternatives or when not to use it, so it falls short of a 5.

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