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

With no annotations provided, the description carries the burden. It discloses that calculations happen locally with no external API dependency, that it returns only a single numeric result, and that it does not fetch live market data. This provides useful behavioral context beyond the schema, though it omits edge-case behaviors or detailed return formatting.

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 about six sentences, each adding distinct value: what it does, supported types, return format, differentiation from sibling, usage guidance, and market data caveat. No filler or repetition; it is dense yet concise.

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 6 parameters, multiple calculator types, no output schema, and no annotations, the description covers purpose, usage, alternatives, and key behavioral constraints. It could mention how to handle invalid calculator types or result precision, but the schema fills parameter needs, making it fairly complete for decision-making.

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 already describes all 6 parameters with 100% coverage, including accepted calculator_type values and per-parameter required context. The description adds nothing about parameter syntax or units beyond what the schema provides, so 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 clearly states it performs common financial calculations with a specific list of supported types, and explicitly distinguishes itself from financial_calculator as a lighter variant returning only a single numeric result. This makes it unique among siblings and gives a clear verb+resource+scope.

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?

Explicitly states when to use lite vs full calculator: 'Use financial_calculator_lite when only the headline figure is needed. Prefer financial_calculator when the agent needs a full breakdown...' Also directs to stock_quote, crypto_price, or currency_convert for live market data, making alternatives clear.

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