payments_custom_provider_marketplace_app_update_capabilities

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

The description discloses no behavioral traits. It never states that the operation modifies the app's capability settings, what side effects occur, or whether it requires special permissions. The annotations do indicate non-readonly, non-destructive, idempotent behavior, but the description adds no context beyond that, and it does not explain what 'update capabilities' actually entails.

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?

While extremely short, this is under-specification, not conciseness. It is a single noun phrase with no structure, no sentence, and no separation of concerns. It does not earn its place for information content and is effectively a placeholder.

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?

Given the tool has three parameters and no output schema, the description should explain what the tool does, what 'update capabilities' means, and what the expected outcome is. It provides none of this. An agent cannot correctly determine how to invoke or interpret the result from this definition.

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 input schema has 100% description coverage for all three parameters, including the required 'supportsSubscriptionSchedules'. The description adds no further meaning; it does not reference or clarify any parameter relationships. Since the schema already documents the parameters adequately, the description does not need to compensate, but it adds zero value.

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 'Custom-provider marketplace app update capabilities' is a noun phrase that almost exactly repeats the tool name. It provides no action verb, no explicit resource, and no clarification of what 'capabilities' means. It is a tautology and does not distinguish the tool from any sibling.

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?

The description offers no guidance on when to use this tool, what conditions warrant it, or which alternatives exist. It does not mention any exclusions or comparisons to related payments tools. An agent has no context to select it over other payment operations.

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