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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, destructiveHint=false. The description adds valuable context beyond these: it specifies the output scope ('Returns search volume and competition data, NOT keyword rankings') and mentions the external requirement ('Requires Google Ads to be connected and an Ads account selected'), which is behavioral information not present in annotations.

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 description is four sentences, front-loaded with the core function, then usage guidance, alternative, prerequisite, and output clarification. Every sentence earns its place; no fluff. It is detailed but structured efficiently for an AI agent.

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?

Despite no output schema, the description covers the output type (search volume, competition, bid ranges) and explicitly what it does NOT return (keyword rankings). It also covers prerequisites and directs to integrations. Combined with high schema coverage and rich annotations, the description is complete for agent decision-making.

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%, with each parameter having a clear description (e.g., keywords: 'The exact keywords to look up'). The main description reinforces the 'SPECIFIC list of keywords' idea but does not add meaningful semantic detail about language, geo, or network parameters beyond what the schema already provides. The baseline of 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?

The description clearly states the tool's function: 'Get average monthly search volume, competition level, and top-of-page bid ranges for a SPECIFIC list of keywords, with no expansion into related terms.' It uses a specific verb and resource, and explicitly distinguishes from the sibling tool get_google_ads_keyword_ideas by noting 'no expansion into related terms'.

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 explicit usage guidance: 'Use this when the user already has keywords in mind and wants them sized' and points to the alternative for discovery: 'For discovering new keywords instead, use get_google_ads_keyword_ideas.' It also states the prerequisite (Ads connected/account selected) and directs to the integration page, plus clarifies not to use for rankings.

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