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

Annotations already declare readOnlyHint=false and non-destructive, so the write nature is covered. The description adds genuinely new behavior: Markdown-to-builder-page conversion, the in-chat website card fallback, and the fact that websiteUrl triggers brand/content extraction. It does not cover permissions or failure modes, so it stops short of 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, then input constraint, then prerequisite, then edge cases. Every sentence carries operational information with no filler.

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?

With an output schema, full annotation coverage, and 100% schema description coverage, the description's job is workflow and edge cases, which it delivers: prerequisite ordering, no-website card behavior, and user-supplied URL handling. 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 100%, so the baseline is 3, and the description earns above it: it explains the markdown format in prose, warns against JSON/HTML, and adds a selection rule for websiteUrl ('Use their own site, not a client's'). The cardId/websitePromptResume internals are left to the schema, which is appropriate.

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 and resource ('Create a new proposal from plain Markdown content') and immediately constrains the input format, distinguishing it from any structured-page creator. The reference to set_website as the prerequisite step makes it tellable apart from siblings 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 an explicit ordering rule ('Call set_website first, before drafting') plus a conditional fallback path when no website exists, and instructs what to do when the user supplies their own site. This is real when-to-use guidance tied to a named sibling.

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