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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful behavior beyond that: it strips navigation and ads from articles, handles HTML and plain-text, and does not work on PDFs or login-gated pages. It does not mention rate limits or failure behavior, which keeps it from a 5.

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 tight sentences. The primary capability and output shape are front-loaded, followed by processing behavior and then hard exclusions. No filler and nothing restates the tool name.

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 values need no explanation, and annotations cover the safety profile. The description supplies scope, output format, and exclusion boundaries, leaving only minor gaps such as rate limits or failure/error behavior.

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 (public http(s) URL) and max_chars (truncation length) are already fully documented in the schema. The description adds no syntax, format, or default information beyond that, so the baseline 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?

States a specific verb (Read) and resource (one public web page), and immediately specifies the output form (clean markdown with title, site, author, publish date). The 'one public web page' scoping plus the HTML/plain-text vs PDF/login exclusions lets an agent distinguish it from siblings like find_archived_page or wikipedia_lookup without opening a 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?

Gives clear when-to-use context and explicit exclusions ('not PDFs or pages behind a login'), which tells the agent when the tool will silently fail. It stops short of naming alternatives, e.g. routing dead links to find_archived_page or reference material to wikipedia_lookup, so it is strong but not fully explicit.

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