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

No annotations are provided, so the description carries the full burden. It adds genuine behavioral context by explaining the sign convention (positive = overage, negative = refund) and that the operation is non-blocking, but it omits error behavior, idempotency, and the fact that the handle ties sub-agents to one budget.

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 dense sentences, front-loaded with the action and followed by a behavioral note. Nothing is wasted, though the parenthetical could be tighter.

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 4-parameter mutation tool with no annotations, no output schema, and low schema coverage, the description explains the core reconciliation concept well but leaves parameter usage and error/retry semantics unaddressed.

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 only 25% (only 'handle' is documented). The description conveys the sign semantics relevant to the numeric inputs but never names usd, tokens, or note, so the other three parameters remain undocumented in both schema and description.

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 and resource: report the actual usage minus the reserved amount after a call. It clearly delineates this reconciliation step from the reservation step (budget_reserve) and status querying (budget_budget_status), so an agent can place it in the workflow without opening a sibling schema.

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?

Gives clear context for when to call it ('After a call'), which is the key trigger. It stops short of naming the complementary siblings (open_budget/reserve) as explicit alternatives, but the sequencing is inferable.

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