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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, and the description still adds substantial operational context: permission requirements, America/Los_Angeles inclusive date semantics, provider ordering with unstable tie-breaking, non-exhaustive data due to omitted top rows/anonymized queries, and a warning that average position is not a ranking. That is exactly the extra behavioral layer annotations cannot convey.

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, prerequisites, date semantics, capabilities, and caveats are front-loaded, and each sentence carries distinct information. It is dense and slightly list-like, but no sentence is pure filler; the trailing endpoint path is the weakest inclusion.

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 9-parameter, nested-object, read-only tool with no output schema, the description covers access requirements, scope, caveats, and most parameter behavior. It does not describe the response envelope or pagination/total-count behavior, which an agent assembling multi-page reads would still need.

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%, so the description carries the burden and mostly succeeds: it explains filters as AND filters, final/all data state, offset/limit pagination, a separate live comparison range, and the date timezone. It leaves gaps on the meaning of 'final' vs 'all', the searchType enum values, and the limit/offset bounds, so it does not fully compensate.

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 sentence names a specific verb (read) and a specific resource set (clicks, impressions, CTR, average position) scoped to Search Console data sliced by page/query/date/country/device. That scope differentiates it cleanly from siblings such as get_website_analytics or get_advertising_performance.

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?

It gives clear context: only valid for the selected verified tenant-bound Search Console site, requires search:read plus Marketing module read access, and no global site/token fallback exists. The 'cannot silently merge with GA4 dates' line implicitly steers agents elsewhere for GA4 data, but no sibling tool is named explicitly as the alternative.

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