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

Annotations already declare readOnlyHint and non-destructive, so the safety profile is covered. The description adds genuinely useful context beyond that: no lookup credits consumed, a fixed 28-day comparison window, and the critical guardrail that a false 'linked' value means the integration is not connected and clicks must not be fabricated.

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?

Four short sentences with zero filler, and the core metric list plus time window lead the text. The telegraphic phrasing ('Does not spend lookup credits') is slightly clipped but does not cost clarity.

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 structure needn't be explained, and annotations cover the safety profile. The description still supplies the freshness window, credit cost, and the linked=false behavior – the main things an agent needs to interpret and trust the response – though it could say more about what happens when the project isn't connected.

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?

There is one parameter with 0% schema description coverage – the schema only constrains projectId to a UUID. The description implies it identifies 'one project' but gives no guidance on where to obtain a valid projectId (e.g., via list_projects), so it only partially compensates for the gap.

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?

Names a specific verb (get) and resource (Google Search Console clicks, impressions, CTR, average position) scoped to one project, which is far more informative than the title alone. It does not explicitly contrast with siblings like get_rank_changes or get_competitor_overview, leaving some differentiation to inference.

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?

States the scope (one project, last 28 days plus previous 28 days) and notes that no lookup credits are spent, which implies 'call freely.' However, it never says when to prefer this over sibling tools such as get_rank_changes or get_seo_briefing, so the choice is left implicit.

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