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

Although annotations already declare destructiveHint=true, the description discloses precisely what gets destroyed: any file not included in the call is deleted. This is exactly the sort of behavioral context annotations cannot convey. It also adds hard operational limits (200 files per call, 1 MB per file) that describe real-world constraints on invocation. No contradiction with annotations.

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 sentences, zero filler. The most critical fact (full replacement with deletion of unlisted files) is front-loaded, followed by usage guidance and limits. Every sentence earns its place.

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 operation with an output schema, annotations, 100% parameter coverage, and an explicit usage note, this is nearly complete. The only gap is that it never names the sibling write_site_files as the non-destructive alternative, which would help an agent deciding between the two tools.

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 schema documents both parameters well. The description adds genuine value beyond it: the 'notes' parameter's semantics as a complete replacement set (anything absent is deleted) reinforces and extends the schema's 'complete new file set' wording, and the 1 MB per-file limit is a constraint not present in the schema.

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 states a specific verb and resource ('Replace ALL files on a site with a new set') and immediately clarifies the tool's distinguishing destructive scope — unlisted files are deleted. This cleanly separates it from the sibling write_site_files and delete_site_files, so an agent can identify the right tool 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?

The description gives an explicit when-to-use directive ('Use when rebuilding a site from scratch'), which clearly scopes the tool's appropriate context. It does not explicitly name the alternative (write_site_files) for non-destructive updates, but the context provided is unambiguous enough for correct selection.

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