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

Annotations already declare readOnlyHint/idempotentHint/non-destructive, and the description adds substantial behavior beyond them: the exact thresholds defining each category (position 5-20 with impressions, under half the expected clicks, lost 10 clicks and 20% vs prior period), that brand searches are excluded, and that items carry a clicks_at_stake monthly estimate ranked together in top_actions.

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 and the four categories are front-loaded before the routing sentence, and each clause carries distinct information. It is dense and long, but no sentence is filler; the single mega-sentence is the only mild readability cost.

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?

With no output schema, the description carries the return-value burden and does so: it names the four ranked lists, the top_actions container, and the clicks_at_stake field. Combined with the safety annotations, an agent has everything needed to call and interpret it correctly.

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 schema already documents defaults and ranges for days, site, limit, include_brand and min_impressions. The description reinforces a few of these (brand exclusion, 'real impressions', period-over-period comparison) but adds no syntax or format detail beyond the schema, 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?

States a specific verb and resource ('The SEO work a Search Console property is asking for, ranked in one call') and enumerates the four opportunity kinds it returns. It names adjacent siblings (page_audit, gsc_search_analytics), so an agent can distinguish it from the broader GSC tools without opening their schemas.

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?

Gives explicit routing: 'Start here when the user asks what to work on, what to improve first or for quick wins; then open the pages with page_audit or gsc_search_analytics.' The entry condition and the follow-up tools are both named, leaving nothing to inference.

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