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

Beyond the annotations (readOnlyHint: true, destructiveHint: false), the description discloses the 2-credit cost and that it is charged even when no results are found, plus the default sorting by volume. This adds practical behavioral detail that annotations do not cover, without contradicting them.

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 short sentences front-load the core purpose, then cover cost and return format. Every sentence adds value, with no filler or redundancy.

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?

The description covers cost, return sorting, and included metrics, but does not explain when to prefer this tool over siblings, nor the structure of the returned items beyond mentioning fields. Given no output schema and moderate complexity, it is adequate but has clear 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%, so all parameters are documented. The description adds extra meaning for 'limit' by explaining it returns the top rows by volume, and clarifies the default of 50, but does not elaborate on country or confirm_quote_id beyond the schema. Baseline 3 is appropriate.

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 clearly states that the tool returns long-tail keyword suggestions containing the seed keyword, along with metrics like volume, KD, CPC, and intent. It is specific about the output and distinguishes itself from related tools like keyword_overview by focusing on suggestions rather than overviews, though it doesn't name a sibling explicitly.

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 provides no guidance on when to use this tool versus alternatives such as related_keywords or keyword_questions. It mentions cost and returns, but lacks any 'use this when' or 'instead of' statements, leaving the selection to inference.

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