Reopen Card

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

Annotations already indicate this is a write operation that is not destructive, and the description adds that the card becomes 'active again' and that closures are undone. This is useful but does not go much beyond the obvious semantic meaning of 'reopen'; it does not mention prerequisites, permissions, or behavior if the card is already active. A 3 is appropriate given the annotation coverage.

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 two short sentences with no filler. The core state change is front-loaded, and the use cases are stated immediately after. Every sentence contributes meaning, making this an efficient and well-structured description.

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 simple two-parameter state-change tool with no output schema, the description plus annotations cover the core purpose, the precondition ('previously closed'), and the intended use cases. There is no critical missing information for an agent to call it correctly, though a note about what happens if the card is already open would be a minor addition.

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 fully describes both required parameters, including the important distinction between card_number and card_id and how to obtain account_slug. Since schema description coverage is 100%, the description does not need to add parameter details, and the baseline of 3 applies.

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 uses a specific verb ('Reopen') and resource ('previously closed card') and clearly states the result ('make it active again'). It distinguishes this tool from the sibling fizzy_close_card and leaves no ambiguity about the state transition it performs.

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 explicitly says when to use it: 'resume work on completed cards or undo accidental closures.' This gives clear context and implies the tool is only for previously closed cards. It does not explicitly mention exclusions or compare it with sibling tools like fizzy_update_card, but the usage guidance is strong enough for an agent to select it appropriately.

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