edit_user_star_subscription

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

Annotations already indicate readOnlyHint=false and destructiveHint=false, so the agent knows this is a mutation. The description adds that it can cancel or extend a subscription, which is useful but does not disclose side effects (e.g., changes to user's access, payment implications) or what happens with the given telegram_payment_charge_id. It does not contradict annotations.

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?

The description is a single concise sentence that front-loads the action. It earns its place with no filler, though it is arguably too brief for the tool's complexity.

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 three required parameters, no output schema, and the complexity of subscription management, the description is insufficient. It does not explain return values, the role of telegram_payment_charge_id, or how to specify an extension. The tool name and schema leave significant gaps that the description should fill.

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?

Only user_id has a schema description (33% coverage). The description adds a hint that is_canceled likely controls cancel vs. extend, but it does not explain telegram_payment_charge_id or the exact boolean semantics. The description fails to compensate for the low schema coverage.

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 clearly states the tool edits a user's Star subscription and specifies the two modes (cancel or extend). It uses a specific verb and resource, which differentiates it from siblings like refund_star_payment. However, it lacks detail on what 'extend' entails, leaving some ambiguity.

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?

No guidance is provided on when to use this tool versus alternatives such as refund_star_payment or create_chat_subscription_invite_link. The description gives no context about prerequisites, typical scenarios, or exclusions, leaving the agent to infer usage from the name and schema.

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