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

Annotations already declare readOnly/idempotent/non-destructive, so the description is not burdened with safety. It adds genuinely non-schema context: the Google Search Console connection requirement, the dashboard URL to fix it, and the multi-account property-resolution behavior — details the agent could not infer otherwise.

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 sentences, each carrying distinct information: capability, use cases, prerequisite with remediation, and account-resolution semantics. Front-loaded with the capability, though the account-resolution sentence is a lower-priority detail placed last.

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 read-only, four-parameter tool with a fully documented schema, the description covers what the schema cannot: authentication prerequisite, connection flow, and multi-account behavior. It omits any mention of data freshness/lag (a known GSC characteristic) or row limits, which would be the remaining gaps.

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%, including the searchType enum and its discover/googleNews caveat, so the schema does the heavy lifting. The description adds no parameter-level meaning (e.g., date-range limits or default window), so 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+resource+scope: daily search performance trends (clicks, impressions, CTR, position) over a date range. This is clearly distinguishable from siblings like get_gsc_query_trend or get_gsc_page_trend, which are entity-specific, while this one is account/property-wide per day.

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?

Provides concrete use cases (spotting ranking changes, traffic drops, algorithm update impact) plus a hard prerequisite and remediation link. It stops short of naming alternatives such as get_gsc_page_trend or get_gsc_query_trend for drilling into a specific page or query, so routing is implied rather than explicit.

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