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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds the precondition that the campaign must be sent, which is genuinely useful behavioral context, but says nothing about result ordering, pagination behavior, or what happens for unsent campaigns.

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?

A single front-loaded sentence with no filler and no redundancy. It is efficient, though its brevity leaves little room for the routing guidance an agent would benefit from.

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 simple three-parameter read tool with full schema coverage, annotations, and no output schema, the definition is adequate. However, it never specifies which domain-level statistics are returned, leaving a real gap given the absence of an output schema.

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 100% and all three parameters (campaign_id, page, limit) are documented in the schema, so the schema does the heavy lifting. The description adds only the implicit constraint that campaign_id refers to a sent campaign, which is marginal beyond the structured fields.

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 ('Get') and resource ('domain-level performance statistics') scoped to a sent campaign, which distinguishes it from click/open report siblings. It stops short of naming the exact metrics returned, so the purpose is clear but not fully sharpened against adjacent report tools.

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: the phrase 'for a sent campaign' hints that the campaign must already be sent, but there is no explicit when-to-use, when-not, or named alternative among the many sibling report tools (get_campaign_clicks, get_campaign_opens, analyze_campaign).

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