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

With no annotations, the description carries the full burden and does well: it discloses payment ($0.0045 USDC via x402 on Base or Solana), that output is a fixed schema and cached by content, and that model outage or daily cap is refused before payment. What's missing is behavior on fetch failures (paywall, 404, robots-blocked) and whether the brief varies between runs.

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 use condition, then Input/Output/Example/Price in tight labeled fragments — every clause carries a distinct fact (fields, schema contract, caching, payment rail). No filler or repeated material from the schema.

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, but the description enumerates the returned keys (markdown, title, brief{headline, summary, key_points, entities, topics, source_language, content_type}) and covers cost, caching, and refusal conditions — enough to invoke and budget correctly. Error/edge-case behavior would complete it.

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% and the schema already documents url, flags=1 (prompt-injection signals) and the max_chars default of 60000, so the description adds no meaning beyond the structured fields. Baseline 3 is the ceiling given how little the description contributes here.

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?

Names a specific verb+resource (read a page and produce an English brief) plus scope (any-language input). The title and description together make the dual output (Markdown + brief) unambiguous, but the description never names the close sibling web_read or explain how it differs, so sibling differentiation is left to inference.

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?

'Use when an agent needs a page in any language read and briefed in English' gives a clear triggering condition, and the example URL shows invocation form. No explicit when-not or alternative routing is stated even though web_read / convert_to_markdown exist as cheaper sibling paths, so it falls short of a 5.

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