Fetch URL

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

With no annotations, the description carries the full burden and mostly delivers: it discloses the fetch fallback chain (GitHub API → YouTube/Reddit fast paths → Crawl4AI headless → raw HTTP), 24h caching, and that responses are a paginated window with a continuation footer. It omits failure modes and what happens when a URL in a batch fails.

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?

Four sentences, no filler, purpose front-loaded first and mechanics after. The middle sentence packing three fetch backends into one line is dense but still scannable.

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 nine-parameter tool with no annotations and no output schema, the description does the necessary work: it explains the return shape (window + footer), pagination, and alternate return modes. Missing only error/partial-failure behavior for the multi-URL case.

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% with descriptions on all nine parameters, so baseline 3 applies. The description adds only marginal meaning — clarifying that `query`/`find` replace the page head and that the footer supplies `offset` — but the schema already explains each of these.

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 ("Read public URLs as markdown") with useful scope qualifiers (PDFs included, public only). It never names the siblings crawl_site or search, so the agent must infer that this is single/few-page reading rather than site crawling.

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 gives real intra-tool routing guidance ("`query` or `find` return passages instead" of the page head) but says nothing about when to choose this over crawl_site or search. Usage is implied by "public URLs" rather than stated as an explicit selection rule.

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