expenses_runway

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only states the output concept (balances + net burn) but does not disclose any side effects, return format, or requirements such as authentication or data freshness. There's no indication of whether this is a read-only operation, which is a notable gap given the lack of 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 extremely concise—a single noun phrase with no wasted words. It front-loads the two key outputs. However, it is so terse that it relies entirely on the reader's prior knowledge of financial runway concepts, and the lack of a verb makes it less clear as an instruction.

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 there is no output schema and no annotations, the description alone must explain what the tool returns and when to use it. It fails to clarify the meaning of 'runway' or how this differs from other expense tools. An agent cannot confidently determine the return format, the units of the burn, or whether 'spending-account' includes all cash accounts. It is under-specified for a tool with no required parameters and a single optional one.

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 documentation covers the 'months' parameter at 100% (it has a description and default value). The tool description adds no additional semantics beyond what the schema already provides, which matches the baseline score of 3. There is no extra context about how months affects the calculation or what values are 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 identifies the resource as 'spending-account balances' and specifies the data type 'trailing monthly net burn', which distinguishes it from siblings like expenses_spend (which likely returns raw spending) and expenses_outstanding. However, it uses a noun phrase rather than an explicit verb like 'get' or 'calculate', leaving the action implied.

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?

There is no guidance on when to use this tool versus the many expense-related siblings. The description does not state that this aggregates balances and burn for runway analysis, nor does it contrast this with tools like expenses_spend or expenses_recurring. An agent would have to infer its purpose from the name alone.

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