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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds real value beyond that: no account is required, the caching behavior is surfaced through the fresh parameter's 15-minute cache note, and it discloses that the result contains a link to a visual report. Rate limits and error behavior remain undisclosed.

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?

Three tight sentences with the purpose front-loaded, followed by usage context and practical extras; nothing is padded. The closing sentence about the visual report link is slightly redundant given an output schema exists, keeping it just short of a 5.

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 annotations covering safety, the schema covering both parameters, and an output schema handling return values, the description only needs to supply scope and context, which it does well (platforms, tag types, pre/post-launch timing, no-account requirement). The one real gap is the absence of any hint about how this differs from check_site_previews, a directly adjacent sibling.

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 both url (example.com/blog/post) and fresh (skip 15-minute cache after deploying a fix) fully documented in the schema. The description adds no parameter-level detail beyond what the schema already provides, so 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?

States a specific verb and resource (scores how a page looks when shared) and enumerates the target platforms, which is far richer than the title alone. It does not, however, differentiate itself from the near-identical sibling check_site_previews, leaving the agent to guess which plural/singular variant to pick.

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?

"Useful before launch or after changing meta tags" gives a clear triggering context for invoking the tool. There is no explicit when-not guidance or named alternative (e.g. versus check_site_previews or create_previews), so the routing decision is only partially resolved.

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