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

Annotations already declare readOnlyHint=true / destructiveHint=false, so the safety profile is covered. The description adds genuinely useful boundary context the annotations cannot: external payments are settled per call via x402 and are deliberately not reflected as a balance. It stops short of describing refresh timing or caching.

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 sentences, front-loaded with what is reported and closing with the one exclusion an agent might otherwise misread. No filler.

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 output schema, the description carries the return-value burden and does list the reported fields (Earned DAC, Trial DAC, days left). For a zero-required-param read tool this is close to complete; only the exact response shape remains unspecified.

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?

There is a single optional auth_token with 100% schema description coverage, including header/env fallback and precedence rules. The description adds nothing about parameters, which is acceptable given the schema fully documents them, but it also does not reinforce the optionality.

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 names a specific verb (Check) and resource (DAC balances) and enumerates what it reports: Earned DAC balance plus Trial status with remaining Trial DAC and days left. It does not explicitly distinguish itself from the sibling get_trial_status, which is the one nearby tool an agent could confuse it with.

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?

Usage is only implied - an agent infers it should call this when it needs to know its balance. There is no explicit when-to-use guidance, no prerequisites, and no routing away from alternatives such as get_trial_status or get_dac_ur.

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