reserve_llm_budget

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

Beyond the annotations, the description adds meaningful behavioral detail: atomicity and fail-closed behavior on ledger errors or exhaustion. It does not discuss retry/idempotency semantics, but idempotentHint=true already provides that signal and there is no contradiction.

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 short sentences with zero filler. The action and target resource are front-loaded, and the failure behavior is stated in a compact second sentence.

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 low-complexity two-parameter tool with annotations covering idempotency and non-destructiveness, the description adds atomicity and fail-closed semantics. It does not describe the success return value, but no output schema exists and the core behavioral profile is adequately covered.

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 schema describes daily_cap_usd, and the description only loosely implies amount_usd via 'reserve USD'. It does not clarify units, positivity constraints, or how amount_usd interacts with daily_cap_usd. At 50% schema coverage, the description provides only marginal compensation for the undocumented amount_usd.

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 names a specific operation ('reserve'), the resource ('USD against the developer key's daily LLM budget'), and even identifies the underlying ledger key ('spend:llm_budget'). This distinguishes it clearly from the many read-only account and usage 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?

There is no explicit guidance on when to call this tool versus alternatives such as get_developer_key_usage or get_my_usage. The intended context is implied by the verb 'reserve', but no when-to-use or when-not-to-use conditions are stated.

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