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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavioral context beyond that: view-specific date defaults and the fact that with_volume joins to the SQP week containing the snapshot date. It omits response/pagination behavior, but an output schema exists to cover that.

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?

The definition is a single front-loaded sentence that names the resource first, then enumerates the three views with their defaults. Each clause earns its place, and there is no filler, though the dense per-view enumeration is somewhat packed.

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?

With 18 parameters, an output schema, and full annotations, the description needs to add mode-selection context rather than restate structured fields, and it does so across all three views. It is complete enough for an agent to select this tool and a view, with only sibling routing left unaddressed.

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 schema already documents all 18 parameters, including the view enum and per-view date fields. The description restates the view semantics rather than adding syntax or format detail beyond the schema. Baseline 3 is appropriate when the schema carries the parameter burden.

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?

The description gives a specific verb ('Return') and resource ('keyword rank snapshot data from the keyword rank table'), then distinguishes the three modes (positions/changes/with_volume). It is clear what the tool does, but it does not differentiate itself from closely related siblings such as get_current_rank, get_keyword_performance, or get_sales_ranks.

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 description gives strong in-tool routing guidance: it states what each view returns and each view's default behavior (trailing 7 days, two most recent snapshots, latest snapshot). This tells the agent when to pick each view. It does not, however, state when to reach for this tool versus sibling rank tools, so it stops short of full when/when-not guidance.

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