shelter_runway

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the description doesn't need to restate these. It adds the context of daily budget and payday, which is useful, but it doesn't disclose any additional behavioral traits such as how the breakdown works or if there are any assumptions about spending. The description is consistent with 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 very concise, using an em-dash to provide a compact summary in one line. It gets to the point without fluff. It could be slightly more structured, but for a simple tool it's efficient.

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 provides enough context. The annotations cover safety, and the parameter is clear. The output is not detailed, but given the simplicity, it's adequate.

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 only parameter, includeBreakdown, is well-documented in the schema with a clear description. The tool description does not need to add more since schema coverage is 100%. However, the description could mention how the breakdown affects the output, but that's optional.

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: calculating how many days until money runs out, with a summary of budget, payday, and safe-to-spend. It distinguishes from siblings like shelter_status and shelter_forecast by focusing on the cash runway metric. However, it could be more specific about the output being a number of days or a time period.

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 usage for financial planning (daily budget, next payday, safe-to-spend) but does not explicitly state when to use this vs. alternatives like shelter_forecast or shelter_affordability. No direct comparison or exclusion criteria are provided.

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