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

Annotations already flag destructive=true and idempotent=true, and the description adds substantial context beyond them: prior state is preserved in revision history, attributed to this API key's label, and is rollback-able. It also explains the non-obvious return of editorUrl and what handing it back does, which is genuine behavioral disclosure.

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, front-loaded with the core action and its full-replacement constraint. The third sentence is dense and slightly run-on, but every clause carries information an agent needs about the return value.

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?

Complete for a destructive mutation with no output schema: it covers the write semantics, the audit/rollback behavior, the message requirement, and the one returned field (editorUrl). Nothing an agent needs to call 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 coverage is 75%, and the description adds real meaning for `design` (must be the complete document) and `message` (persisted into revision history so the label explains the change). It adds little for `name` and `designId`, but the message semantics are non-obvious and well covered.

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 (Replace) and resource (cloud design) with the key scope constraint that the whole document is sent. An agent can immediately distinguish it from create_design (new object) and get_design (read) without opening a 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?

Gives strong in-tool usage rules ('send the whole document — there is no partial update', include a message), which is actionable context. However, it offers no guidance on when to choose this over siblings like create_design or review_design, leaving alternative selection to inference.

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