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

With no annotations, the description carries the full burden. It does add genuine non-schema context: output is deterministic hashes and diffs, and each call costs $0.001 USDC on Base via x402. However it omits payment/auth prerequisites, failure modes, rate limits, and what happens with bad selectors.

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 short sentences, front-loaded with the core purpose, then mechanism, then cost. No filler. Could be slightly denser but nothing is wasted.

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?

For a 9-parameter tool with no annotations and no output schema, the description leaves many behaviors unexplained (selector semantics, truncation limits, timeout, ignore lists). An agent cannot confidently populate most optional parameters.

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 0% across 9 parameters, so the description must compensate. It only alludes to previous_hash/previous_text and the diff/hash outputs; selector, ignore_selectors, max_diff_chars, max_text_chars, timeout_seconds, and include_current_text get no explanation at all.

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 and resource: 'Detect whether a webpage changed' with the comparison mechanism (previous hash or previous text). Clear and distinguishable from scrape/extract siblings by its change-detection intent, but it never explicitly names an alternative such as web-monitoring-snapshot.

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?

Usage is only implied through the compare-against-previous-hash/text mechanism; there is no explicit when-to-use or when-not-to-use guidance relative to siblings like web-monitoring-snapshot or canonical-web-scrape. The cost disclosure implies a paid gating condition but no routing advice.

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