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

Annotations cover safety (readOnlyHint, destructiveHint=false, openWorldHint), and the description adds substantial context beyond them: output structure {url, markdown, truncated}, 2-5s latency, the 8,000-character cut with a truncated flag, login-page refusal, and the x402 payment model including that failed/invalid calls are not charged. This is rich, non-redundant behavioral disclosure.

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?

Three dense but purposeful sentences: output/format first, then routing to the sibling, then constraints and payment. Nothing is wasted and the key facts are front-loaded.

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?

With no output schema, the description carries return-value responsibility and does so precisely (shape, truncation, timing). Payment, failure, and access constraints are all covered, so 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 description coverage is 100% and there is a single url parameter, so the schema already documents format and the private/local-address restriction. The description adds no syntax or format detail beyond what the schema provides; 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 (returns/extracts) and resource (main text of one public web page), and specifies the exact output shape (clean markdown, unchanged, not summarized, up to 8,000 chars). It explicitly distinguishes itself from bob_summarize, so an agent can route between the two without opening schemas.

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 an explicit when-to-use condition ('when you need the page's own words') and names the alternative plus the condition that selects it ('use bob_summarize for a short version'). It also states exclusions: pages needing login cannot be read.

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