Preview how a body will render

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

Beyond the readOnly and idempotent annotations, the description explains the conversion behavior and explicitly states that nothing is created or touched. This adds useful safety context beyond the annotation flags alone.

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 sentences with no wasted words. The core operation and safety guarantee are front-loaded, followed by a concrete use case.

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?

The rich input schema and safety annotations carry most of the context, and the description clearly explains the tool's purpose and when to use it. The output format is not specified, but 'show what it produced' is adequate for an agent to invoke and inspect the result.

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%, and the schema already thoroughly documents body and body_format, including supported markdown, embed URL behavior, paywall syntax, and table handling. The description adds no new parameter-level details, so the baseline of 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?

States a specific operation: convert a body to Substack's document format and show the result without persisting anything. It clearly distinguishes itself from draft-mutating siblings like set_draft_body or create_draft.

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 a concrete use case: check embeds, paywalls, or nested lists before writing to a draft. It doesn't name alternatives explicitly, but the 'before you write it to a draft' contrast positions it well against write/save tools.

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