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

With no annotations, the description carries the full burden and does so richly: it discloses the 9-credit per-call cost, that every call is billed, that there is no offset/paging because a second page would be a second charge, and that an exactly-full result set is capped rather than complete. It even prescribes the workaround (raise the row count in a single call). This is exactly the operational context annotations would otherwise provide.

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?

Front-loads what the tool returns before moving to usage, cost, and the paging caveat. Every sentence adds operational value; nothing is redundant given the absence of annotations.

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?

No output schema exists, and the description fully covers the return shape (keywords plus a 0–1 relevance score), the cost model, the truncation semantics, and the correct workaround. Nothing an agent needs to invoke and interpret this tool 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 100%, so the baseline is 3. The description exceeds that by explaining the semantics of 'limit' beyond the schema: results are capped at the requested count and a full-page response signals truncation, not completion, with the instruction to raise the count in one call rather than page.

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?

States a specific verb+resource: 'keywords Bing associates with one specific page.' The phrase 'one specific page' explicitly differentiates it from sibling tools like Bing_Site_Keywords and Bing_Keyword_Ideas, which operate at other scopes. An agent can select this 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?

Gives a concrete usage context ('Point it at your own article...') and explains the diagnostic value of a focus-keyword mismatch. However, it never explicitly names which sibling to use instead when a page-level Bing keyword view is the wrong choice, so the routing guidance is implicit rather than complete.

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