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

The annotations already declare a complete safe-read profile (readOnlyHint, idempotentHint, destructiveHint=false), so the bar is lower. The description usefully implies retention limits ("retained") and per-delivery granularity ("individual delivery outcomes"), which annotations do not convey, but says nothing about pagination, result volume, or retention window.

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 the key distinguishing detail ("individual delivery outcomes") is not buried. It is arguably too terse for the gaps it leaves, but as a structure it is clean and earns its space.

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 output schema covers return values and annotations cover safety, so the description need not repeat those. What remains missing is exactly the burden the description carries: how this differs from list_server_events and get_server_routine, and what the routine identifier refers to. Adequate but with real gaps.

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% for the single required parameter, and the description does not compensate: it never mentions routine_id, what a routine is, or where the 64-hex-character identifier comes from. The schema's regex pattern is the only constraint, and the description adds no semantic meaning on top of it.

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 verb ("Read") and a resource ("observed events and individual delivery outcomes"), so the general shape is clear. However, "retained observed events" is undefined jargon, and nothing distinguishes this from close siblings like list_server_events or get_server_routine. An agent cannot tell from the text which of these to pick.

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?

There is no statement of when to use this tool, when not to, or which sibling it replaces. The presence of list_server_events and get_server_routine in the sibling list makes this omission costly, since the routing decision is exactly what the description should settle.

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