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

Annotations already declare readOnlyHint=true/destructiveHint=false, and the description adds genuinely useful behavior an agent needs: auth is required, every response carries the next cursor, and polling is supported via a since cursor. It stops short of describing event shape or rate limits, so not a 5.

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?

Three short sentences, front-loaded with what the tool returns and who consumes it, with no filler. Could be tightened slightly but every clause carries information.

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 does the right thing by stating the return payload (event log plus a cursor per response) and the auth requirement. Event-level structure remains unspecified, but for a 2-param read tool that is a minor gap.

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 coverage is 100% and the schema already documents both id and since, including the note to reuse the previous response's cursor. The description restates the cursor mechanism and adds the ?since=<unix-millis> format hint, but adds little meaning beyond what the schema already provides, so the baseline 3 applies.

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 resource ('full event log for a physical-operator onboarding session') and its consumer (the chat console activity sidebar), so the agent knows exactly what it retrieves. It is not confused with pcc_onboard_session_status or pcc_chat_history, but it never names a sibling to differentiate explicitly, which keeps it short of a 5.

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 'supports incremental polling via ?since' sentence implies the polling use case, and 'feeds the activity sidebar' implies context, but there is no explicit when-to-use guidance versus pcc_onboard_session_status or pcc_chat_history. Usage is inferable rather than stated.

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