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

Beyond the annotations (which already declare readOnlyHint=false and destructiveHint=true), the description discloses the credit cost (FREE), the bring-your-own-key auth requirement (BING_WEBMASTER_API_KEY), and concrete failure modes with payloads ({ ok: false, reason: 'not_configured' } and 'no_matching_site'). This is exactly the value-add context annotations cannot carry.

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?

It is front-loaded with the core action in the first sentence, followed by mutation/cost, listing limitation, and auth/error details. Slightly dense and mixes internal operation names (AddBlockedUrl/RemoveBlockedUrl) with prose, but every sentence carries distinct information with no filler.

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, the description compensates by explaining the error/return shape and auth prerequisites. Combined with the mutation warning and the note that no listing counterpart exists, an agent has everything needed to call this correctly.

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 every parameter including action, entityType, and requestType is already documented in the schema. The description only restates the add/remove intent (stop vs resume) without adding format or edge-case detail beyond the schema, so the baseline 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 names a specific verb pair (add/remove = block/unblock) and a specific resource (one URL in Bing search results for a project's matched site). It is clearly distinguishable from the many other Bing siblings (get_bing_*, save_bing_crawl_settings, update_bing_query_parameter) which are read or config tools rather than URL-level block/unblock.

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 for use (stop or resume showing a URL) and flags the operational constraint that there is no GetBlockedUrls, so this is add/remove-only. It does not, however, explicitly name a sibling alternative or state when-not-to-use, so it stops short of the top band.

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