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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, and the phrase 'without changing records or spending credits' largely restates those. The one genuinely additive detail is that the estimate includes a wallet balance check, which is useful behavioral context.

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-loaded with the core action ('Estimate campaign cost') followed by scope and safety details in three tight sentences. Little waste, though the trailing safety sentence is largely redundant with annotations.

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?

No output schema exists, so the description should say more about what the estimate returns (cost breakdown fields, wallet balance structure). It conveys purpose and safety but leaves return content underspecified for a tool whose value is the estimate payload.

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 nested path.id parameter with generic 'Resource ID' schema text (0% meaningful coverage). The description's reference to 'campaign' implies id is a campaign id, adding modest meaning, but it doesn't clarify path nesting or what id must reference.

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 (estimate) and resource (campaign cost) with added scope that it includes a wallet balance check. However, it does not distinguish itself from the very similar sibling dealmachine_get_mail_campaigns_id_properties_estimate, leaving ambiguity about which estimate to use.

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?

'for launching a campaign' implies pre-launch usage, but there is no explicit when-to-use, when-not, or alternative routing despite several competing estimate/wallet siblings. Usage is only inferable from context.

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