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

Annotations already declare a non-read-only, idempotent, non-destructive, open-world mutation, so the safety profile is covered. The description adds genuinely useful context beyond that: a Premium gating requirement and the reset-to-auto behavior when a field is left blank. It stops short of 5 because it promotes a share-image field that the schema does not expose, which could mislead an agent about available behavior.

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?

Two sentences, front-loaded with the operation, followed by the two caveats an agent needs (Premium gate, blank-reverts behavior). Tight and waste-free. The only drag is the share-image clause, which spends words on a capability the schema does not support.

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?

An output schema exists so return values need no explanation, and annotations cover the safety profile, leaving the description responsible only for gating and default semantics, which it supplies. It is nearly complete for a 2-param tool, with the main gap being the unsupported share-image mention and the absence of partial-update clarity.

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 0%, so the description carries the burden. It does map language to both parameters ("the title and description search engines show") and explains the blank-equals-default rule. But it adds no length/format guidance for seoTitle (60) or seoDescription (160), and its third named item (the share image) has no corresponding parameter, leaving the semantic picture partly inconsistent.

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 pairs a specific verb ("Set") with the concrete resources it governs: the search-engine title, the search-engine description, and the social share image. That scope cleanly separates it from siblings like update_page_appearance and get_page_settings. It loses a point because the share-image capability it advertises is not backed by any parameter in the schema, slightly overstating what the tool does.

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?

"Part of Premium" and "Leaving a field blank goes back to the one Kulhad writes" give real usage context: a tier requirement and a clearing/default semantic. However, it never states when to reach for this tool versus alternatives, nor that omitting a field leaves it untouched (as opposed to clearing it), which is the ambiguity an agent most needs resolved.

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