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

Goes well beyond the annotations: states the exact cost (2 AI credits from the monthly pool, not the org's own key), that an unconfirmed call runs nothing and charges nothing, and the idempotency/replay behavior. Annotations only say readOnlyHint=false/openWorldHint=true, so this description carries and succeeds at the behavioral burden.

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?

Front-loads the core action and the safety-critical confirm protocol before peripheral details. It is longer than strictly necessary, but nearly every sentence (cost, confirm gate, approval scope) carries operational weight.

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 paid, confirm-gated mutation with no output schema, the description supplies everything an agent needs: cost, preview behavior, confirmation loop, and the shape of the quote response. No output schema is needed because the quote contract is described inline.

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?

Schema coverage is 80%, so most parameters are already documented. The description adds meaning the schema does not: the credit-charging semantics gated on confirm, and the requirement to resend the same arguments on the confirmed call. It adds real value over the baseline 3.

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+resource ('Translate a text ... into another language') with scope qualifiers (keeping tone, emojis, hashtags). This cleanly distinguishes it from siblings like adapt_caption and write_caption, which do not translate.

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?

Gives an explicit two-phase protocol (call without confirm for a quote, then re-call with confirm:true after a clear yes) plus a rule for how far one approval extends. It stops short of naming sibling alternatives like adapt_caption, so it is clear context rather than full when/when-not routing.

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