Get email report

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

Beyond the readOnlyHint annotation, the description discloses substantive behavior an agent cannot get from structured fields: results are counts only and never identify individuals, and clicks/opens are suppressed below 10 deliveries to prevent re-identification. It also conditions the abTest block on the campaign having tested a subject. These are exactly the quirks that would otherwise cause misreading of the numbers.

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?

The 'Read only' lead and the output inventory are front-loaded and every clause carries information. The middle sentence runs long with stacked noun lists, but no sentence is filler.

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?

With no output schema, the description carries the return-value burden and does it well, specifying both the metric set and the abTest sub-structure. Remaining gaps are the required campaignId argument and behavior for campaigns that haven't sent yet.

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% and the description never mentions campaignId at all — not its meaning, not its expected format, not that it is required. With one required parameter documented nowhere, the description fails to compensate for the schema gap, though the resource framing ('report of an email') implicitly points at an identifier.

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?

The description names a concrete resource (the performance report of a sent email) and enumerates exactly what it contains: sent, delivered, bounces, complaints, unsubscribes, clicks/opens, clicks per link, time series, and abTest breakdowns. An agent can tell this is a metrics read, not the campaign settings read that postfjord_get_campaign or postfjord_get_analytics would give. However, it never explicitly contrasts itself with those siblings, leaving the routing inference to the agent.

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 report of an email that went out' signals this is for post-send analysis, and the privacy note hints it's for aggregate performance rather than recipient-level inspection. There is no statement of when to prefer it over postfjord_get_campaign, postfjord_get_analytics, or postfjord_list_campaigns, and no note that it only makes sense after a send.

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