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

Annotations already declare destructiveHint=true and non-idempotent; the description adds real context beyond that by disclosing that target 'header'/'footer' REPLACES the site header/footer, and that contentOverrides sets final copy in the same call. It stops short of stating reversibility or required permissions, so not 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?

Front-loaded with the core action and mode selection, then constraints, then alternatives and guide link. Dense but each clause carries information; only slightly long.

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 complex 9-param, destructive, no-output-schema tool, it covers the critical decision points (which mode, header/footer replacement, copy overrides, alternative tool, guide). Missing only return/result behavior and permission requirements, which are secondary.

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%, so the baseline is 3, but the description adds meaning: the 'exactly one' rule for slug/sourceNodeId, the header/footer replacement semantics, and that contentOverrides is keyed by the block's lib_* ids. This goes beyond the raw schema descriptions.

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 ('Stamp a section as-is') and resource, and enumerates the two mutually exclusive modes (library `slug` vs clone of `sourceNodeId`). It clearly distinguishes itself from the sibling add_nodes, so an agent can tell what this does 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?

Explicitly frames the tool as 'a shortcut for when an existing pattern genuinely fits' and names the alternative path ('to design a section for this business, use add_nodes with get_block as reference'). It also points to a guide via get_style_reference, covering when and when-not.

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