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

Annotations already flag destructiveHint=true and readOnlyHint=false, so the safety profile is covered; the description adds the permission requirement, the audit-history line, and the important 'only what you pass changes' partial-update contract. Some of the empty-value semantics overlap with the schema, which keeps it from a 5.

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 dense sentences, front-loaded with the verb and resource, and every clause conveys a rule the agent needs. Mild redundancy with the schema on empty caption/sites/days keeps it from top marks.

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 destructive mutation with no output schema, the description covers the partial-update contract, permission gating, audit behavior, and the empty-value edge cases an agent would otherwise get wrong. Nothing essential to calling it correctly 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 schema already documents embedId, caption, sites and days, including the empty-value behavior. The description restates those same empty-value rules rather than adding new syntax or format detail, so 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 and resource ('Change an embed of a wiki page's scene') and enumerates the mutable attributes (caption, sites, term). It implicitly separates itself from create/delete siblings by stressing that the link is kept so framing sites keep working, though it never names those siblings outright.

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 a clear precondition ('Only for somebody who may edit the page') and a side-effect note ('a line in its history'), which helps an agent decide whether this is the right call. It stops short of explicitly pointing to create_wiki_embed/delete_wiki_embed as alternatives for the cases this tool doesn't cover.

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