Invoke Firecracker Function

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

Annotations already declare destructive/openWorld/idempotent, but the description adds context they cannot: per-invocation billing charged to the account, that async invocations do not retain output, that a key is auto-generated per call, and that replays may surface a replayed=true marker. These are operationally critical traits beyond the structured hints.

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?

Front-loaded with the action, then cost, then execution mode, then idempotency. Four dense sentences with no filler; each one carries a distinct, decision-relevant fact.

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?

A paid, asynchronous-by-default, idempotent invocation tool with no output schema needs exactly this: cost disclosure, sync/async tradeoff, polling path, and retry semantics. Nothing required to call it correctly is missing.

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 100% so the baseline is 3, but the description adds the rationale behind wait ('when output/logs are needed') and the auto-generation/reuse lifecycle of idempotency_key, which the schema only partially captures. acknowledge_usage_billing is left to the schema, so it is not a full 5.

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 ('Invoke a Firecracker Function') and immediately differentiates itself from the sibling get_function_invocation by assigning that tool the polling role. An agent can tell what this does and how it relates to list_functions/get_function without opening a 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 explicit conditions: use wait=true when output/logs are needed, otherwise poll get_function_invocation with the returned invocation_uuid, and reuse an explicit idempotency_key only for an exact retry. This is the when/when-not/alternative pattern done well.

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