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

Annotations already declare readOnlyHint=true and destructiveHint=false, so no safety restatement is needed. The description adds useful behavioral context: it requires a connected GSC account, reports connection status, and provides data that 'no other tool has'. No contradiction found.

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?

Two sentences, front-loaded with the actionable use case and specific outputs. 'Free.' and 'numbers no other tool has' are brief value context rather than padding.

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 one-parameter, read-only overview tool with strong annotations, the description covers purpose, prerequisite, and connection-failure behavior. It is complete enough for an agent to select and invoke 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?

The single optional range_days parameter is fully documented in the schema as '28 (default) or 90'. The description adds no extra semantic detail about the parameter, so the baseline 3 is appropriate.

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?

Description opens with 'Use this before touching SEO on the user's own site' and enumerates the specific data view: clicks/impressions trend, device split, and period comparison from the user's connected Google Search Console. This distinguishes it from sibling tools like gsc_pages and gsc_queries while making the resource and scope explicit.

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 an explicit when-to-use directive ('before touching SEO on the user's own site') and notes the prerequisite (GSC connected) plus a fallback ('this tool tells you if it is not'). It does not name sibling tools or explicitly state when not to use it, so it stops short of a 5.

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