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

Goes well beyond the annotations (readOnly/idempotent/openWorld=false) by disclosing exactly what html_to_markdown strips (scripts, styles, forms, media) and returns (markdown plus page title), and how markdown_to_html handles raw HTML (rendered as text) and unsafe link schemes (rendered as their text). This is concrete behavioral detail that materially affects safe invocation.

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 dense per-direction detail, with no filler. Slightly long and comma-heavy, but each clause carries real information about output behavior.

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?

No output schema exists, so the description correctly explains return values for both directions (markdown + title, or html). Combined with the safety and auth-free context, an agent has everything needed 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 50%, with the direction enum and data field documented in the schema. The description adds meaning by explaining what each direction value actually produces and its safety handling, compensating for the gap on direction semantics; data itself is only lightly described.

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+resource (convert HTML<->Markdown) and the two direction modes, so the agent knows exactly what the tool does. It does not explicitly differentiate from the closest sibling html_to_pdf, relying on the resource name to distinguish, which keeps it just below a 5.

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 clear rationale for when each direction is useful ('so a fetched page reads with fewer tokens' for html_to_markdown, 'so the html can go into a page as it is' for markdown_to_html). It never names an alternative tool or states when-not to use it, so no explicit exclusion guidance.

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