Daily metrics for entities over a date range, in the reporting currency

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful facts not in the annotations: daily granularity, that values are expressed in the reporting currency, and the underlying POST endpoint. It says nothing about how missing data days, currency conversion, or entity defaults are handled.

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?

A single front-loaded sentence with zero redundancy and no filler. It is efficient, though the brevity comes at the cost of omitted parameter guidance rather than being a model of tight prose.

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?

A read-only analytics query with a seven-field nested body, no output schema and no parameter documentation leaves the agent guessing about defaults, row shape and optional filters. For this complexity the description should say at minimum what entityIds omission means and what a response row looks like.

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% and the body nests seven properties, yet the description only gestures at date range and currency. It adds no meaning for entityType (campaign/ad_group/ad), entityIds, firstParty or lookbackDays, including what happens when entityIds is omitted, which is the most consequential ambiguity here.

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 names a specific resource (daily metrics for entities), a scope (over a date range) and a unit (reporting currency), plus the REST endpoint. That is enough for an agent to know what the tool returns, but it never distinguishes it from siblings such as analytics_breakdown, analytics_compare or analytics_pacing, which all operate on the same entity/metric space.

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?

There is no when-to-use or when-not-to-use guidance and no mention of the near-identical analytics_* siblings. An agent has to infer from the name alone whether this or analytics_breakdown is the right call.

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