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

Annotations already declare readOnly, idempotent and openWorld=false, so the safety profile is covered. The description adds that sanitize strips scripts from the output and that no URL is fetched, but it never states whether sanitization applies to HTML→Markdown as well, nor what happens to unsupported Markdown constructs.

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 short sentences, front-loaded with the primary action. 'to is html or markdown' is telegraphic and slightly awkward, but no sentence is wasted.

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?

An output schema exists, so return values need no explanation, and the safety profile is annotation-covered. Still missing for a 3-parameter tool: any description of the 'text' input and whether sanitize is ignored in the Markdown direction.

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 description coverage is 0%, so the description must carry the burden. It explains 'to' (redundant with the enum) and 'sanitize' (genuinely additive beyond the boolean name), but says nothing about 'text' — the core input payload — so coverage is only partial. Partial compensation lands at 3.

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, with both directions named ('Markdown to HTML, or HTML to Markdown'), and adds the scope boundary that it does not fetch a URL, which implicitly separates it from fetch_page_markdown. It stops short of naming any sibling explicitly or differentiating from convert_data_format.

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 direction is selected via 'to is html or markdown', which is usable guidance, and the no-URL-fetch sentence rules out the fetching sibling. There is no explicit when-to-use/when-not statement or named alternative.

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