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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered; the description adds ordering ('newest first'), a plan gate ('Requires an Indie plan (trial counts)'), and which fields each specialized change type carries. It omits pagination/continuation behavior, which is the only notable gap.

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?

Single dense paragraph, front-loaded with the resource and scope, and the ordering rule and use case land before the parenthetical detail. The long parenthetical enumeration of change types is information-dense but earns its place; slightly heavy for one sentence.

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?

No output schema exists, so the description carries return-value burden — it discloses ordering and the fields for the two specialized types, plus the plan requirement. It could say more about the shape/fields of the common change records, but what an agent needs to call the tool correctly is present.

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% with an enum and default documented, so baseline is 3. The description goes further by explaining what the `header` and `in_app_event` enum values actually yield (action added/changed/removed plus artwork; title, kind, dates), which the schema does not.

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 (change history for a tracked app) and enumerates the exact change classes it returns: releases, metadata edits, screenshot swaps, price changes, category moves, header swaps, and iOS In-App Events. An agent can distinguish this from sibling tools like sonar_app_overview or sonar_alert_events purely from the description.

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 a concrete use case — 'correlating rank movements with what the app (or a competitor) changed' — which implies when to reach for it. It also names the `type` filter's role ('omit for all types') and the plan prerequisite. It stops short of naming alternatives (e.g. sonar_alert_events) or stating when NOT to use it.

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