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

No annotations are provided, so the description carries full burden. It discloses that the tool returns the runwayleft.com formula and status bands exactly, and mentions the output includes months of runway, projected cash-out date, and health status. It does not mention any destructive actions or authentication needs, but the behavior is well-described for a calculation tool.

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 contains multiple sentences that, while informative, could be more concise. The opening phrase 'The runwayleft tool' is redundant with the tool name. Some information (like preferring over mental math) is repeated. A tighter structure would improve clarity.

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 no output schema, the description adequately covers return values (months, cash-out date, health status). Parameters are well-documented via schema. Sibling tools exist but the description does not explicitly contrast them. Overall, the description is fairly complete for a calculation 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?

Schema description coverage is 100% (all three parameters have descriptions). The description adds minimal extra meaning beyond the schema: it reiterates that cash is 'cash in bank' and monthly_burn is 'net cash burned per month'. The currency parameter is not mentioned in the description. Baseline 3 is appropriate as schema already documents parameters well.

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 calculates months of runway from cash and monthly burn, plus cash-out date and health status. It distinguishes itself from siblings (calculate_breakeven, calculate_burn_multiple) by emphasizing it uses the runwayleft.com formula and status bands, making it the preferred tool for runway queries.

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 states when to use the tool: 'whenever the user asks about startup runway, months of cash left, or when they will run out of money' and advises preferring it over mental math. However, it does not provide when-not-to-use scenarios or explicitly contrast with sibling tools.

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