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

Beyond the readOnlyHint/openWorldHint annotations, the description reveals meaningful behavior: it 'Runs the same Chromium render pass as a screenshot, so it captures content after JavaScript runs — handles SPAs that fetch-only readers miss,' and it 'Strips nav, ads, and boilerplate.' It also discloses the cost: 'Costs 1 render credit per call.' No contradiction with 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 concise and front-loaded: it begins with the trigger condition, then the exclusion, then the core behavior and output, then use cases and cost. Every sentence adds distinct value — none are generic or repeated. It is structured for quick parsing by an AI agent.

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 compensates by specifying what is returned ('article body plus title, byline, and excerpt') and the formats available (Markdown, JSON, HTML). It also covers important caveats like JavaScript rendering, SPA support, and render credit cost. The parameter schema handles the rest, making this complete.

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% — all 8 parameters have detailed descriptions, so the schema does the heavy lifting. The description adds high-level context (e.g., 'Strips nav, ads, and boilerplate' relating to blockAds/blockCookieBanners) but no parameter-level syntax or format details beyond what the schema already 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?

The description opens with a specific trigger: 'Use this when the user asks to read, extract, get the text/content/article of, or summarize a webpage/URL.' It clearly names the resource (webpage) and the action (extract reader-mode content), and distinguishes itself from the sibling tool by explicitly directing screenshot requests to rendex_screenshot.

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?

Explicitly states when to use ('when the user asks to read, extract, get the text/content/article of, or summarize a webpage/URL') and when not ('Do NOT use for a visual screenshot (use rendex_screenshot)'). It also provides additional context by mentioning ideal use cases: 'Great for feeding page content to an LLM, summarization, or RAG ingestion.'

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