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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety and side-effect profile is established. The description adds behavioral context beyond these annotations by specifying the outputs (gross burn, net burn, runway) and the unique 'health label' benchmarked to SaaS funding-stage expectations. It does not contradict any annotation.

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 with no filler. The first sentence front-loads the core purpose and inputs, while the second adds the unique health-label output. Every word earns its place, making it highly concise and well-structured.

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?

The tool is a straightforward calculator with four simple numeric parameters, all fully documented in the schema. Annotations provide safety context, and an output schema exists (as stated in context signals), so the description need not explain return values. The description adds the health-label benchmark, ensuring complete context for an agent to select and invoke the tool 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?

Schema description coverage is 100% with each parameter already explained in detail (e.g., starting_cash: 'Cash on hand at the start of the period, in dollars. Use the bank balance plus any short-term equivalents.'). The description adds no additional parameter-level meaning, but this is acceptable because the schema carries the full burden. 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's purpose: 'Compute a startup's gross burn, net burn, and runway from starting cash, ending cash, the period in months, and optional monthly revenue.' This includes a specific verb ('Compute'), a resource ('startup's gross burn, net burn, and runway'), and enumerates the inputs, which distinguishes it from all sibling calculator tools. The additional mention of a 'health label benchmarked to standard SaaS funding-stage runway expectations' further differentiates it.

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 when to use the tool by listing the required parameters (starting cash, ending cash, period months) and optional monthly revenue, giving the agent clear contextual cues about the data needed. However, it does not explicitly mention alternatives or when not to use it. The schema provides additional usage guidance for the period_months parameter (e.g., 'Use 1 for last month, 3 for a quarter, 12 for the trailing year').

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