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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds one useful behavioral fact: it operates on already-fetched rows, so it is purely presentational and does not itself pull insights. It does not disclose the rendered output form or whether rendering has side effects such as persisting a report artifact.

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 seven-word sentence with no filler, and the core action is front-loaded. It is efficient, though the extreme brevity borders on under-specification rather than genuine conciseness.

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 tool with 8 parameters, a strict connection-context pattern, an enum level, and nested row/series payloads, one vague sentence is insufficient. The presence of an output schema excuses explaining return values, but the description still omits what the report is for, what the rows should contain, and how this differs from the sibling export/console render 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 8 parameters, so the description carries the burden and largely fails. It alludes only to "rows" and a report title concept; nothing is said about level (the enum), series, currency, date_range, notes, or the connection_context token pattern. The agent gets no added semantic guidance for parameters the schema does not document.

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 verb ("Show") and a resource ("fetched performance rows as a report"), so the agent knows this is a presentation/rendering step rather than a data fetch. However, it is close to a restatement of the tool name and gives no differentiation from presentation siblings such as render_ads_console, render_ad_previews, or the export tools. The exact nature of the output (chart, table, formatted document) is left entirely unstated.

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?

The word "fetched" faintly implies rows must be obtained beforehand, but there is no explicit when-to-use guidance, no prerequisite statement, and no named alternative among the many rendering/export siblings. The agent must infer the full call context from the schema alone.

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