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

Annotations already declare readOnlyHint, openWorldHint and destructiveHint, so 'Changes nothing' is largely redundant and safety is covered. The one genuinely additive behavioral note is 'Totals are the site's true totals', which warns that per-row sums may not reconcile with reported totals — a real trap in this data. No mention of rate limits, auth scope, or result-size behavior.

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?

Three sentences with no filler; the core action and comparison basis are front-loaded before the enumeration of output categories. The dense enumerated list in sentence one is justified because it tells the agent exactly what rows it will get back, though the trailing 'Changes nothing' is redundant against the readOnlyHint annotation.

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 an eight-parameter tool with no output schema, the description carries the burden of describing returns and does so by naming the result categories, and the fully-covered schema handles invocation details. It is only slightly short of complete: how 'rising' is defined/thresholded and when to prefer this over search_console_performance are left implicit.

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 all eight parameters (days, fresh, limit, end_date, site_url, start_date, min_impressions, exclude_query_regex) are already documented in the schema, including the 3-day look-back lag and regex intent. The description adds no parameter-level detail beyond what the schema supplies, 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 and scope: it compares a window against the equally-sized window immediately before it, and enumerates the exact output categories (rising, falling, new and lost queries, losing-position searches, rising/falling pages). This is clearly distinguishable from search_console_performance or search_console_summary by its delta framing, though it never names a sibling to sharpen the contrast.

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?

The comparison framing implies the use case (period-over-period movement analysis), so an agent can infer when this beats the sibling summary/performance tools. However, it contains no explicit when-to-use, when-not, or 'use X instead' guidance across the eight sibling search_console_* tools, leaving the choice to inference.

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