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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds genuine business context beyond that: a run held at pending_review has not been charged and nothing has been sent to the ad platform. It says nothing about pagination behavior or the maximum page size, which matter for a log-reading tool.

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 tight paragraphs: purpose and event scope first, the motivating question and state semantics second, return contract last. No sentence restates the title or wastes space, and the most decision-relevant content is front-loaded.

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 correctly supplies the return shape (total, count, offset, items, has_more, next_offset), which is the main gap it needed to fill for a read-only list tool. It is nearly complete, missing only paging guidance and parameter meaning, which are minor for a straightforward log fetch.

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% across five parameters, so the description carries the burden, and it only partly does. Listing offset, has_more and next_offset in the return shape implicitly signals that this is a paginated endpoint, but limit (max 50), response_format (markdown vs json), and the ideaId/runId pairing are never explained.

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 gives a specific verb and resource ('chronological event log for an Ad Run') and enumerates the event categories covered (provisioning steps, status changes, review holds, errors), which distinguishes it from a state-returning sibling like get_ad_run. It stops short of naming the sibling it differs from, so an agent must infer that get_ad_run returns current status while this returns history.

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?

It supplies a concrete diagnostic scenario ('Answers "why is my run not live yet?"') and explains the meaning of the pending_review state, which tells the agent when this tool is the right call. It offers no explicit exclusion or named alternative for the case where the agent just wants current run status, leaving that boundary implicit.

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