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

Annotations already declare readOnly=false, idempotent=true, destructive=false and openWorld=true; the description adds substantial value on top: pricing (USD 0.003, no free tier), 'never charged' on failure, sub-1s latency, hard caps (200,000 bytes, 20,000 tokens, 100,000 XML elements, 32 nesting), image/HTML omission rules, and link-scheme restrictions. It stops short of describing pagination or the exact error surface, but that is minor.

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 verb and return shape, then caps and pricing. Dense but every clause carries information; a few fragments ('Inline Markdown only, with optional title and A4/Letter page size') duplicate earlier sentences and could be trimmed.

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?

For a paid conversion tool with an output schema, the description covers inputs, limits, cost, failure behavior, safety caveats and injection warning. Nothing an agent needs in order 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 schema already documents all four parameters, including the base64-vs-url behavior and the title length limit. The description largely restates these rather than adding new semantics, so the baseline 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 verb and resource ('Convert Markdown to Word') and immediately enumerates the supported constructs. It is clearly distinguishable from siblings like convert_pdf_to_word, markdown_to_html and convert_document_to_markdown, which run in the opposite direction.

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?

Usage is implied through constraints ('Inline Markdown only', 'a4/letter page size') and the output=url tradeoff note, but it never names an alternative tool or an explicit when-not condition. The agent must infer that markdown_to_html is the cheaper path for non-document output.

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