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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false), so the re-stated 'Read-only, costs nothing' adds little. However, the description usefully discloses what the call actually returns in each mode — account-id field, row levels, breakdown dimensions, entity types — which is genuine behavioral context.

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?

Front-loaded with the core purpose and packed into two sentences with no filler. The first sentence is somewhat run-on, but every clause (both modes, the specific outputs, the use cue) earns its place.

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?

For a one-parameter discovery tool with an output schema and full annotation coverage, the description covers both invocation modes, the content returned, and the motivating use case. Nothing an agent needs to call it correctly 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?

Schema description coverage is 0% for the single 'platform' parameter, so the description carries the burden — and it does: the empty-string default is explained as 'lists every platform', while a supplied value returns that platform's account-id field, levels, and breakdown dimensions. That is the key semantics an agent needs, though accepted platform values are not enumerated.

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+resource: it is a capability-discovery tool for the unified read tools, and it names the exact siblings whose behavior it describes (get_report, list_entities). An agent can distinguish it from those siblings without opening a 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: 'Call this whenever you are unsure which level/breakdown/entity name to pass.' It also explains the two invocation modes (no argument vs. platform argument). It does not state any when-not-to-use condition, so it falls short of full routing guidance.

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