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

Annotations already declare readOnlyHint=false and idempotentHint=true, so the MUTATION note and toggle semantics largely align. The description adds genuine context beyond them: cost model (free/no credits), byok auth requirement (BING_WEBMASTER_API_KEY), and specific failure responses ('not_configured', 'no_matching_site').

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-loaded with the action and a compact mapping of the underlying vendor operations. Info-dense with little waste, though the parenthetical vendor operation names overlap with the tool name and add some bulk.

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?

For a 3-parameter mutation with 100% schema coverage and annotations, it covers the missing pieces: cost, auth requirement, read companion, and even the error-return shape in lieu of an output schema. An agent has everything needed to call it 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 coverage is 100% and the action enum values are fully documented in the schema (add/remove/enable/disable). The description confirms the single-parameter scope but adds no format, syntax, or edge-case detail beyond what the schema provides, 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?

Precise verb+resource: add/remove/toggle a query-string parameter Bing ignores when canonicalizing URLs, scoped to a project's matched site. It explicitly names the sibling read half (get_bing_site_overview's queryParameters / GetQueryParameters), so an agent can distinguish it from adjacent tools without opening the 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?

Clear context: it states this is the write half of the query-parameter family and points to the read counterpart, plus flags that it is FREE (no credits). It lacks an explicit 'do not use this to read' exclusion or preconditions beyond the error reasons, but the routing signal is strong.

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