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

With no annotations, the description discloses the most important behavioral trait: it returns metadata only and explicitly notes the POST body is not stored. It also states the ordering (newest-first), which is a behavioral detail an agent needs to know.

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 description is two sentences, with the primary action and filter context in the first sentence and a critical caveat in the second. No superfluous words.

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 description covers the tool's purpose, return type limitation, and data retention nuance, compensating for the lack of an output schema. The schema handles parameter details, so the overall package is sufficient for an agent to invoke it correctly.

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?

All six parameters are fully documented in the input schema, including formats and enums, so the description need not repeat them. The description adds no parameter-specific syntax beyond what the schema provides.

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 specifies a clear action ('List recent deliveries') and identifies the resource type ('for a webhook'), with a distinct scope ('pings and fires') and purpose ('for diagnosing failures'). This differentiates it from sibling tools like list_webhooks and list_events.

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 'for diagnosing failures' provides clear context for when to use this tool, but it does not explicitly name alternative tools or exclusion criteria. The sibling list_webhooks is a different operation, so a more explicit when-not would be beneficial.

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