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

Annotations provide readOnlyHint and openWorldHint, but the description adds substantial context: the underlying model (Llama 3.3 70B), that pages are read like /api/read with robots.txt respected, the 12,000-character text limit, and crucially the pricing model ($0.003 USDC via x402 on Base, Solana, or Arc, with failed calls not charged). This goes well beyond the annotations.

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?

The description is front-loaded with the core purpose and packs useful details (model, read behavior, pricing) into a few sentences. The first sentence is a bit long, and the 'Llama 3.3 70B.' fragment is slightly abrupt, but overall it is efficient with no wasted words.

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?

Given that an output schema exists and annotations cover safety/open-world behavior, the description is complete for an agent to call the tool correctly. It discloses pricing, payment chains, read semantics, and input limits, leaving no important operational gap.

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 description coverage is 100%, so the schema already documents all four parameters. The description mentions the 12,000-character limit, length options, and language, but these are largely redundant with the schema descriptions, adding no new syntax or format details.

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?

The description states a specific verb+resource: summarizing a web page (url) or text into short, medium, or bullets. It distinguishes itself from the sibling 'read' by noting 'A page is read as in /api/read,' making clear it returns a summary rather than raw content.

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?

It implies usage (summarize a URL or your own text) and mentions length and language options, but does not explicitly compare against alternatives like text_outline, text_paraphrase, or read, nor does it state when not to use it. Basic context is present but no routing guidance.

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