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

Annotations already cover the safety profile (readOnlyHint, destructiveHint false, openWorldHint), so the bar is lower. The description adds real behavioral context beyond them: the exact-URL matching requirement and the notConfigured: true fallback when no Bing API key exists for the property. It does not discuss rate limits or quota consumption, which would have earned a 5.

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?

Four sentences, front-loaded with the tool's purpose, then the drill-down relationship, the URL pitfall, and the notConfigured edge case. Each sentence earns its place; the first is dense but not padded.

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 an output schema present, return-value documentation is not required, yet the description still clarifies that CTR is a 0-100 percentage and position is impression-weighted. It also covers the no-API-key edge case. Only a note on result volume/pagination beyond the schema's 'uncapped' limit is missing.

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 80%, so the schema already documents page, limit, startDate, and endDate including the exact-URL and no-null pitfalls. The description mostly repeats the URL-matching instruction rather than adding syntax or format meaning, so 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 names a specific verb and resource ('The Bing search queries that led to ONE landing page') and enumerates the returned metrics, then explicitly positions itself against sibling get_bing_page_stats as its 'natural drill-down'. An agent can distinguish this from get_bing_query_stats or get_bing_page_stats without opening any schema.

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?

It gives clear context ('the natural drill-down after get_bing_page_stats') and a concrete prerequisite ('Pass the page URL exactly as get_bing_page_stats returns it'), which routes the agent correctly. It does not state when NOT to use it or name a competing per-page alternative, so it falls 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.