Credit packs

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

The readOnlyHint=true annotation already establishes this is a safe read. The description adds genuinely useful behavior beyond the schema: the price currencies (EUR/USD) and the fact that credits never expire, which is a policy trait an agent could relay to a user.

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 terse fragments with no wasted words and the subject front-loaded. However, the absence of a verb makes it read as a label rather than a directive, which slightly undercuts clarity.

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 no input parameters and no output schema, the definition is nearly complete by omission, and the currency/expiry notes cover the key user-facing facts. Still, an agent is not told what a pack entry contains (e.g., credit amount, price field names) or that this is the canonical catalog source.

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 tool takes zero parameters and schema coverage is 100%, so the baseline is 4. There is nothing for the description to disambiguate about inputs.

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 is a noun phrase ('Credit packs and prices') rather than a verb+resource statement, though it clearly implies retrieving the credit-pack catalog. It adds scope (prices in EUR/USD) but does not distinguish itself from sibling retrieval tools like get_balance or create_checkout_link.

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 when-to-use guidance at all. It does not say whether this is the right tool to inspect purchasable packs versus checking an existing balance via get_balance, nor when create_checkout_link should follow.

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