direct_get_statistics

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds one useful behavioral fact beyond that: it may return either completed TSV rows or an offline queue status, hinting at an asynchronous path. However, this is cryptic and leaves unclear when queuing occurs or how to retrieve queued results.

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 no padding. The trailing clause is terse but introduces an ambiguous term ("safe offline queue status") that slightly undermines clarity, though the size itself is appropriate.

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?

An output schema exists so return values need not be explained, but for a 5-parameter tool with 0% schema coverage and no usage guidance, the description is far too thin. It neither compensates for the undocumented parameters nor clarifies how this differs from the several sibling statistics tools.

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 5 parameters. date_from/date_to are self-evident, but field_names, report_type (with its CUSTOM_REPORT default), and campaign_ids have no schema descriptions and no explanation in the description either, so the agent cannot know valid values or semantics for these.

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?

"Read campaign statistics" names a clear verb+resource, but the second clause ("returns completed TSV rows or safe offline queue status") muddies scope and implies an async/offline queue mechanism. It does nothing to distinguish this from siblings like direct_get_goal_statistics or metrika_get_statistics, which an agent must disambiguate by name alone.

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 guidance, no prerequisites, and no mention of alternatives such as direct_get_goal_statistics or metrika_get_statistics. The agent is left to infer applicability from the name only.

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