sitepeek: render a web page to Markdown or a screenshot

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

Annotations only declare the generic read/idempotent/open-world profile; the description goes well beyond by disclosing the SSRF guard (private and internal addresses are refused), latency expectations (0.3-1 s static, 2-3 s with JS), per-render pricing, a free-tier quota (5 static renders per IP per UTC day), and that output is flagged untrusted_content:true. It even states the IP-based rate-limit unit, which no annotation captures.

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?

Dense but front-loaded: purpose first, then sibling routing, then return semantics, cost/quota, and a safety note. Every clause carries information, though the single semicolon-chained block is harder to scan than discrete sentences and the docs URL plus pricing could be trimmed slightly.

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?

An output schema exists, so return values need not be explained, yet the description still adds the one return fact an agent must act on (untrusted_content:true and the instruction to treat page text as data). Combined with cost, quota, timing, and the SSRF constraint, nothing needed to invoke this correctly is missing.

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%, so the schema already documents each parameter and the 3 baseline applies. The description nonetheless adds meaning the schema does not: that js:true implies sandboxed browser execution and a higher price (USD 0.01 vs USD 0.002), and that format selection determines whether viewport width/height matter for screenshots.

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+resource ('fetch a public http(s) URL and return clean Markdown ... or a PNG screenshot') and explicitly distinguishes itself from the two nearest siblings, render_pages_batch and take_website_screenshot. An agent can select it without opening any other schema.

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?

Names both relevant alternatives and the exact condition that routes to each: 'For up to 5 pages use render_pages_batch; for a full-page or JPEG capture use take_website_screenshot.' This is explicit when-to-use and when-to-use-something-else guidance.

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