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

The annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, and the description adds material facts the annotations lack: the tool runs a specific Apify Actor on the caller's own Apify account with pay-per-event pricing at $0.001/page, billed by Apify. It stops short of describing failure behavior for unreachable pages or the 25-URL cap.

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?

Two sentences, zero filler: the first front-loads the returned fields and format, the second front-loads execution location and cost. Nothing is repeated from the schema or annotations.

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 listing the returned fields, and it covers billing and account context. Sibling differentiation and error/failure behavior are the remaining gaps, but for a simple two-parameter read tool this is close to sufficient.

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 both pageUrls and apify_token are fully documented in the schema, and the description adds nothing about URL format, batching, or when the token fallback is needed. Baseline 3 is appropriate since the schema carries the parameter burden.

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?

It uses a specific verb and resource and enumerates exactly what is extracted (title, meta description, OG, Twitter Card, JSON-LD, canonical URL, language, H1s), which clearly separates it from siblings that pull article bodies (extract_article) or full page content (extract_website_content). An agent can choose it without opening the 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?

The description implies usage (extract metadata from web pages) but never states when to prefer it over extract_website_content or extract_article, nor any exclusions such as non-HTML URLs. Usage must be inferred from the listed output fields.

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