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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description still adds domain-meaningful context: this answers the 'did the credit land?' question after an unconfirmed create, and explicitly reassures 'Never spends, never retries' — valuable in a credits context. It does not describe latency or behavior when the key is unknown.

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 compact sentences with the scope exclusion front-loaded before the core question and the read-only guarantee. No filler; every clause carries information.

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?

With rich annotations and an output schema, the description does not need to explain return values, and it covers scope, semantics, and safety. The only gap is routing advice — what to do when the key is unknown or when the check is being made from a conversational context.

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 enum for 'tool' is fully documented, so the schema carries the parameter semantics. The description ties the two parameters to the 'unconfirmed spend' scenario, but adds no format, casing, or key-lifetime detail beyond what the schema states.

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 precise operation (checking whether an unconfirmed app_generate/app_upscale spend actually created a generation) on a precise resource (the idempotency_key). It immediately distinguishes itself from the app_generate/app_upscale siblings, which create the spend rather than report on it.

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 an explicit scope restriction and exclusion: 'For the Veltake app's own screens only — not for a conversation.' That tells the agent both where this belongs and where it does not. However, it never names the alternative an agent should reach for when checking generation status outside the app UI (e.g., get_generation or list_generations) or for confirmed spends.

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