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

Annotations already declare readOnly=true, idempotent=true, openWorld=false and non-destructive, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: the fixed 28-day window and the 'connected is false until connected and synced once' state flag that tells the agent a returned result may be empty for that reason.

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 short sentences with no filler. The core content (metric, window, dimensions) is front-loaded, and the connection-state caveat follows where it belongs.

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?

An output schema exists, so return values need not be explained. For a zero-param read tool, the description covers scope, data returned, time window, and the connection-state caveat — everything an agent needs to call it and interpret an empty response.

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?

With zero parameters, the baseline is 4. The description correctly adds no argument detail because there is nothing to configure, and it does not fabricate parameters.

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 (read Search Console numbers), plus the window (last 28 days) and the exact data returned (clicks, impressions, best articles by clicks). It is highly concrete, though it does not name or contrast with any sibling tool, which is the only thing separating a 4 from a 5.

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?

Usage is implied by the description: an agent can infer this is the tool for a quick GSC performance overview. However, it names no alternatives, no when-not-to-use conditions, and no prerequisites for invoking it, so guidance is only implicit.

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