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

Beyond the readOnly/idempotent annotations, it discloses two non-obvious behaviors: GSC must be connected (with a URL to send the user to) and multi-account properties resolve through whichever account can see them. That auth/setup context is genuinely additive. It stops short of noting pagination or result-size behavior for the rowLimit parameter.

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, front-loaded with what the tool does and what it returns, then prerequisites. No filler, though the multi-account sentence could arguably be deferred to a prerequisites block.

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?

No output schema exists, yet the description states what comes back (top pages within the segment by clicks), plus the connection requirement, which is the main failure mode. With 100% schema coverage on the six parameters, the remaining gap is only the sibling routing guidance.

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%, so the baseline is 3. The description's urlPattern examples largely repeat the schema's own example ('/blog/' or '/products/'), and it adds nothing about rowLimit defaults, date range semantics, or searchType restrictions.

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 (analyze search performance for a URL segment) with concrete examples of segment patterns and even the return shape (top pages by clicks). However, it never distinguishes itself from close siblings like get_gsc_top_pages or get_page_performance, which an agent would also consider for page-level 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?

Usage is implied by the segment-filter framing, and connection prerequisites are spelled out, but there is no explicit when-to-use vs when-to-prefer get_gsc_top_pages or get_gsc_page_queries. The agent must infer the routing decision from the sibling names alone.

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