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

With no annotations, the description carries the full behavioral burden. It helpfully discloses the invocation cost (0.002 USDC), but for an enforcement tool it omits the critical semantics: what happens on a budget violation (deny, throw, or return a verdict), whether it is a dry-run or a hard gate, and any auth requirements.

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?

A single front-loaded clause with zero padding, but it is arguably under-specified rather than concise for a tool with three required nested inputs and no annotations. Nothing is wasted, yet little is delivered.

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?

An output schema exists, so return values need not be explained, but the description is still incomplete for a budget-gate tool: it never states enforcement behavior, the atomic-unit convention, or how the four scopes interact. An agent cannot confidently wire it into a payment flow from this text alone.

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% and the schema includes a worked example, so the three required objects (request, usage, policy) and their atomic fields are already documented. The description adds no parameter meaning beyond the schema, so the baseline 3 applies.

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?

States a specific verb ('Enforce') and resource ('budgets') and enumerates the four budget scopes (per-call, task, session, period), so the function is unambiguous. It does not, however, differentiate itself from the many budget/spend siblings such as delegated_spend_policy or subscription_spend_guard, leaving the agent to infer the boundary.

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 when-to-use guidance, no prerequisites, and no named alternative among the ~28 sibling payment tools. The agent must guess whether this runs before a charge, as a preflight gate, or as an ongoing monitor.

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