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

Annotations already cover readOnly, idempotent, non-destructive and openWorld, so the bar is lower. The description still adds real value beyond them: scripts/styles are dropped on html→md (a data-loss disclosure), the tool is free, and errors surface via isError without charging.

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 primary direction, then flavor, libraries, transformation caveat, pricing and error behavior in four dense, non-redundant sentences. Nothing is padding.

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 present, return values need no explanation. The description covers direction, supported extensions, destructive transformation, cost, and error semantics — everything an agent needs to call it correctly.

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 both parameters (target enum and raw input) are already documented, establishing a baseline of 3. The description restates the two conversion directions but adds no syntax or format detail beyond 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?

States a specific bidirectional verb+resource: convert Markdown to clean HTML or HTML back to Markdown, with the flavor named (GitHub-flavoured: tables, task lists, fenced code). No sibling tool in the list performs format conversion of Markdown/HTML, so it is unambiguously distinguishable.

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 two directions and the default target are made clear, which tells the agent when each mode applies, but it does not name exclusions or alternatives. Since no sibling overlaps, the direction split is enough context to select correctly.

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