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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely useful behavior: robots.txt compliance, public-page restriction, a 1h cache, sha256 of content, and that it costs 1 credit per successful call with an X-API-Key requirement. However, these signals are buried inside a large block of payment/referral prose, which dilutes their utility.

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 first sentence is well front-loaded, but the remainder is a run-on block of pricing packs, x402 purchase URLs, credit accounting, and a referral program with settlement terms—content that does not help an agent invoke this MCP tool and actively obscures the operationally relevant facts.

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-value explanation is unnecessary, and the two parameters are documented in the schema. The core operation plus auth and robots constraints make the definition functionally complete, but the heavy promotional noise and absent failure-mode guidance (e.g., non-public URLs, credit exhaustion) leave real gaps.

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 both `url` and `maxChars` (with its 500-100000 range and default) are already fully documented in the schema. The description adds no additional semantics about parameter behavior, so the baseline of 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 opening sentence names a specific verb and resource ('Fetch a public web page and return clean Markdown') and even enumerates the structural elements preserved (title, headings, links, lists, code) plus a sha256 of the content. Siblings are all unrelated (email, solana, x402 payment utilities), so no differentiation is needed, but the scope qualifiers 'public pages only' and 'Respects robots.txt' sharpen purpose further.

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 states a constraint ('public pages only') but never says when an agent should choose this over any alternative, nor what to do when a page is non-public or robots-disallowed. The rest of the text describes billing mechanics rather than usage selection, leaving only an implied 'use this to read a web page'.

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