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

With no annotations, the description carries the full burden and does most of it: 20 MB size cap, per-page return structure, non-persistence ('Not stored'), and an explicit per-call price ($0.006 USDC via x402). It omits error behavior, timeouts, and what happens if payment fails, which keeps it short of a 5.

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?

Purpose and constraints are front-loaded in the first sentences, and every clause (size limit, persistence, price, format) adds information. The inline example output is bulky but justified because no output schema exists, so it earns most of its length.

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 2-parameter conversion tool with no annotations and no output schema, the description supplies the essentials: input constraints, output structure via example, cost, and storage behavior. Missing failure modes and format default are minor residual gaps.

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 only 50% (the format enum is undocumented in the schema), but the description compensates: it explains the two format values and adds a 20 MB constraint on the URL that the schema does not state. It does not specify a default for format, leaving one small ambiguity.

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 concrete verb+resource (PDF -> text/markdown) plus the output shape ('text per page') and primary use cases (RAG, summarizing, indexing, reading documents). It does not explicitly distinguish itself from plausible siblings like file_convert, web_to_markdown, or image_ocr, so an agent must infer the boundary from the input type alone.

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 situational context — RAG ingestion, summarization, search indexing, and reading reports/papers/contracts/invoices — which tells an agent when this tool fits. However, it never states when not to use it or names the alternative (e.g. use web_to_markdown for HTML, image_ocr for scanned images), so the routing decision is left partly to inference.

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