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

Annotations only say readOnlyHint and openWorldHint, and the description adds substantial behavior beyond that: page sections check their top 20 URLs live, asking for issues re-runs the striking-distance/low-ctr/quick-wins checks, and several sections are explicitly labeled heuristics (ai-queries, traffic-drop, google-updates "timing only, not cause"). One gap keeps it from higher: the mark path "records what the person decided" and the hosted server "keeps the list between sessions," which is persistent state mutation under a readOnlyHint=true annotation — the description should reconcile that rather than leave the agent to notice it.

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?

The bulleted section list is well structured and each section line carries real information. The opening is the problem: a single dense sentence packs all three calling modes, the beta behavior, and the fallback site-list case into one unbroken clause, making the most important routing rule the hardest part to parse. It is long but not padded — the cost is legibility, not 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 10-parameter, zero-required, multi-mode tool with no output schema, the description does the heavy lifting on return content, describing what each section yields (row counts and top rows, per-page share, comparison windows, 28/56-day before-and-after windows). Remaining gaps are date-range scoping across sections and pagination, both delegated to schema descriptions.

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%, so the baseline is 3; the description earns above that by giving meaning the enum values cannot — what each of the twelve sections actually computes, when mark/issues replaces section, what saved contains and why it exists, and what end_date does to google-updates. It does not clarify how start_date/end_date interact with individual sections, which is left implicit.

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 is unusually specific about the verb and resource: it enumerates three calling modes (no site = cross-site weekly audit summary, site = main property report, site+section = one section's rows) and defines all twelve sections by what each computes. An agent knows exactly what the tool returns in each mode. It loses a point only because it never distinguishes itself from the six sibling tools (seo_data, seo_page, seo_index, seo_lint, seo_research, seo_compare), several of which plainly overlap on sections like google-updates and issues.

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?

"Start here" establishes entry-point ordering, and the description gives explicit sequencing rules: run without site first, then with site, then request one section; add mark and issues instead of section to record decisions; end_date selects an earlier google-updates entry. The gate that issues only persists for audited sites and otherwise returns JSON for the agent to save is spelled out. What is missing is when NOT to use this tool and which sibling to reach for instead.

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