shelter_affordability

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

Annotations already establish readOnly, idempotent, and non-destructive behavior. The description adds functional behavioral context by explaining that the tool computes the impact on safe-to-spend and provides a recommendation, giving the agent a clearer picture of what the tool produces.

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 a single, focused sentence with no wasted words. The hyphenated addition clearly explains the output value without restating the tool name or duplicating schema details.

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 is a simple read-only check with three well-documented parameters, the description provides enough context: what is checked, what is affected, and the nature of the output. With no output schema, a bit more detail about the recommendation format could be useful, but it is not required for selecting and invoking the 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?

The input schema already provides clear, complete descriptions for all three parameters (amount, currency, description), so the description adds no extra parameter-level semantics. Baseline 3 is appropriate because the schema fully carries the parameter documentation burden.

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 uses a specific verb ('Check') and a clear resource ('a specific purchase') while defining the output as impact on safe-to-spend and a recommendation. This clearly separates it from sibling tools like shelter_status and shelter_runway, which address broader or different financial questions.

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 phrasing clearly signals when to use the tool: when evaluating a specific purchase against a safe-to-spend position. It does not explicitly name alternatives or give when-not-to-use conditions, but the context is specific enough for an agent to select it over sibling tools.

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