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

With no annotations, the description carries the full burden, and it does disclose a real behavioral trait not present in the schema: cost of 1 credit per call. It is silent on other relevant traits such as whether the page must be statically fetchable, whether redirects are followed, and any rate limits.

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 with no filler: what it returns, the optional filter, and the cost. The core purpose is front-loaded and each sentence earns its place.

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 simple 2-parameter read tool with no output schema, the description states the return shape (links plus anchor text) and the cost. Minor gaps remain around output volume/pagination and static-vs-JS rendering behavior, but nothing blocking for correct invocation.

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 only 50% — url is documented but same_domain_only has no schema description. The description compensates by explaining that flag ('Optionally keep only links on the same domain'), so the semantics of the undocumented parameter are recoverable from the text.

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 ('List every link on a page with its anchor text'), which cleanly separates it from neighbors like extract_content, scrape_page, and sitemap_urls. It stops short of naming any sibling, so sibling differentiation is implicit rather than explicit.

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?

There is no when-to-use guidance, no prerequisites, and no reference to alternatives such as crawl_site (multi-page) or check_urls (validate links). The only usage flavor is the inline note that same-domain filtering is optional, which describes a parameter rather than when to pick this tool.

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