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

Beyond the annotations (which only indicate idempotency and non-destructiveness), the description explains the behavioral effects of each parameter value: caps paid overage, triggers 429 responses, 0 means no overage, and null means unlimited. This adds meaningful context that annotations do not provide.

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?

Two sentences deliver the core action, parameter semantics, and usage context with zero filler. The information is front-loaded and every clause earns its place.

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 simple one-parameter tool with no output schema, the description covers purpose, parameter semantics, and the specific error scenario. It is complete for the tool's intended use.

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 coverage is 0%, so the description carries the full burden for parameter meaning. It thoroughly defines overage_cap_usd, including the meanings of a number, 0, and null, adding value that the schema lacks.

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 states a specific action ('Set (or clear)') and resource ('hard monthly overage spend cap in USD'), and further distinguishes the tool by describing the error recovery context. This differentiates it clearly from sibling tools.

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?

It gives clear context by identifying this as 'the recovery for a spend_cap_reached error', which tells the agent when to use the tool. No explicit exclusions or alternatives are mentioned, but the guidance is sufficient for this specific tool.

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