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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds substantial interpretation context beyond that: UTC vs Pacific date boundaries, the meaning of isCurrent=false, asOfDate semantics, and the measured/verified_zero GSC evidence rule. Since no output schema exists, this disclosure of result semantics is genuinely valuable; only the lack of pagination/size or failure behavior keeps it from 5.

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?

Purpose is front-loaded and each subsequent sentence carries a distinct rule (timezone split, coverage source, isCurrent handling, GSC evidence bounds). It is dense and somewhat repetitive around "partial covered ranges," but no sentence is pure filler.

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 read-only, single-optional-param tool with no output schema, the description covers the important returned fields (trend.date, clicksDate, priorClicksDate, isCurrent, asOfDate, searchConsole coverage) and how to report them honestly. It is thinner on what the top-level "summary" actually aggregates (findings, scores, counts), but nothing critical to a correct call 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 100% and the single windowDays parameter is fully documented in the schema (enum of 7/30/90, default 30). The description adds nothing about the window — not even how the choice affects trend or coverage boundaries — so the baseline 3 applies.

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 first clause gives a concrete verb and resource ("Get Audit summaries and independently bounded trends"), and the following sentences reveal that the payload includes trend dates, GSC clicks, and current/prior coverage. However, "independently bounded trends" is unexplained jargon and the description never distinguishes this from siblings like devtune_get_audit_findings, devtune_get_audit_extraction, or devtune_get_search_rollups.

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 statement of when to call this tool, when not to, or which sibling to prefer for audit findings versus rollups. The conditional instructions ("When isCurrent is false...") govern how to report results, not when to select this tool, so an agent gets no selection guidance.

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