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

Annotations already declare a safe read (readOnlyHint=true, destructiveHint=false), so the bar is lower. The description adds real behavioral context beyond them: positions are only tracked to the top 30, and include_ranking makes the call slower and return a larger payload. It does not cover pagination or rate-limit behavior, but for a read tool that is a minor gap.

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?

Two dense sentences with the resource and its fields front-loaded, and the optional-mode caveat attached inline rather than buried. The field enumeration is long but each item earns its place as return-value disclosure in the absence of an output schema.

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 no output schema and eight parameters, the description steps in to describe the returned field set and the top-30 tracking limit, which is exactly what the agent needs to interpret results. The only remaining gap is routing guidance versus the keyword-specific siblings, which is a usage concern rather than completeness.

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 goes beyond the schema by spelling out what include_ranking actually returns (latest position, traffic, ranking pages, SERP features, best position in period), which the schema only summarizes as 'ranking data'. The other parameters add no description-level detail but are fully documented in the schema.

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?

Specific verb (List) plus resource (keywords tracked for a website) with an enumeration of the returned fields. It is clearly distinguishable from siblings like wincher_get_keyword (single keyword) or wincher_list_groups. The trailing GET path reinforces the resource precisely.

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 implicitly tells the agent to set include_ranking when ranking data is needed and notes the cost tradeoff, and the schema points to wincher_list_segments for segment_id. However, it never states when to prefer this over wincher_get_keyword or wincher_get_keyword_ranking_history, nor any prerequisites beyond website_id.

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