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

Annotations already flag destructive, idempotent, openWorld, and non-readOnly, so the safety profile is covered. The description adds genuinely useful behavior beyond that: it explains how to use idempotency_key on retry to get the original execution, and warns that a new key is a new paid operation. It stops short of stating whether failed jobs are refunded or what happens to the existing execution.

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?

Three short sentences, front-loaded with the core action, then the idempotency mechanics, then the cost warning. No filler or restatement of the name.

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 7-parameter, nested-object, credit-charging mutation with no output schema, the idempotency and cost story is well covered but the payload semantics (items/targets, expected_credits accuracy, options) and failure/refund behavior are not. An agent can call it safely but cannot reason about the arguments from the description alone.

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 description coverage is 0% across 7 parameters, and the description only gives meaning to idempotency_key ('Save a UUID'). export_type, count, items, expected_credits, timezone, options, and detection_token semantics (including the relationship between count and expected_credits) are left entirely to types and a single schema example.

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 specific verbs and resource: charge credits and enqueue export jobs. It clearly separates this from read-only siblings like list_export_jobs/get_export_job, and the word 'confirmed' implies a prior quote step, but no sibling (e.g. quote_export_jobs) is named explicitly.

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 implied rather than stated: 'Charge confirmed credits' indicates this runs after a quote is confirmed, but the description never says to call quote_export_jobs first, nor when not to use this tool. The retry guidance applies only to uncertainty after a call, not to tool selection.

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