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

With no annotations, the description must disclose behavior itself; it clearly marks this as a retrieval operation and lists the returned metrics, which implies no side effects. It does not address error behavior, data freshness, or required permissions, but for a read-only analytics tool this is a moderate but not severe gap.

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 states the action, object, and key metrics with no filler. Every clause contributes useful signal.

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?

The tool is simple, parameters are fully documented, and the core metrics are listed, so an agent can invoke it. Still, without an output schema or a usage note, the description does not define the response shape or how this tool differs from get_message_stats/get_campaign_status.

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%, so the baseline is 3; the description adds no new parameter-level details beyond reinforcing that campaignId identifies the campaign. Optional agentId and accountId are already fully explained in the schema.

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 ('retrieves'), a specific resource ('a specific campaign'), and concrete analytics (delivery rates, read rates, unique engaged users). This separates it from get_campaign_status, which suggests status rather than performance metrics.

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?

The phrase 'in-depth performance analytics' implies when the tool is relevant, but there is no explicit when-to-use guidance or mention of sibling alternatives like get_campaign_status or get_message_stats. An agent must infer the boundary from the tool name and description.

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