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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds only what data is returned (credits and plan) and notes that the alternative endpoint is 'coming soon' — useful, but no auth requirements, caching, or return-shape detail.

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 short sentences, no waste, with the primary purpose front-loaded ahead of the alternative routing. The '(coming soon)' qualifier earns its place by warning the agent that the alternative may not work yet.

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 zero-parameter read with no output schema, the description states what comes back (credits and plan), which is the key missing piece. It falls short only on disambiguating from popcraft_show_plans_and_credits, the sibling that appears to answer a near-identical question.

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, so the schema carries no semantics to supplement and the baseline is 4. The description correctly implies a no-argument, user-scoped read with nothing for the caller to configure.

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?

States a specific verb and resource: getting the user's available credits and current plan. It is understandable on its own, but it does not address the closest sibling, popcraft_show_plans_and_credits, whose name suggests overlapping 'plan/credits' coverage — an agent cannot tell from the description alone which of the two to prefer.

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 routes transaction-history queries to popcraft_transactions, which is a genuine when-to-use alternative. However, it gives no guidance for the much nearer sibling popcraft_show_plans_and_credits, so usage for the overlapping case is left to inference.

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