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

Annotations already declare the safe-read profile (readOnly, idempotent, non-destructive), and the description adds real behavioral value on top: the meaning of each terminal state, the crucial caveat that connected+no_matching_events does NOT mean zero traffic, and that attempt status expires alongside the setup link. That last point is time-sensitivity the annotations cannot express.

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?

Four tight sentences with no filler, front-loaded with the action and its trigger, followed by the state interpretations and the expiry caveat. Every sentence carries operational weight.

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 an output schema present, return values need not be spelled out, and the description still covers the highest-risk gaps: how to read partial success and the do-not-misreport warning. Nothing an agent needs to call and correctly interpret this tool is missing.

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?

One parameter with 100% schema description coverage, so the schema already explains attemptId and its origin. The description restates that provenance plus useful context (it is produced after user authorization), but adds no format or validation detail beyond the schema. Baseline 3 applies when the schema carries the parameter load.

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 and resource ('Check the attemptId ... status') and anchors it to the sibling that produces the input (connect_posthog). An agent can distinguish this read-side status check from the connect_posthog initiation call without opening either schema.

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?

Gives an explicit trigger condition: call this after the user completes authorization, using the attemptId returned by connect_posthog. It also frames how to act on results ('Pending/failed/expired are not connected'), but names no alternative tool for the not-connected case, so it stops short of full when/when-not routing.

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