tor_fetch_onion

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

Annotations already declare readOnly/openWorld/non-destructive, so the safety profile is covered. The description adds genuinely useful non-obvious context: a Tor daemon must be running, DNS-leak prevention is handled via socks5h, and the return is raw HTML rather than parsed output.

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 action and resource, then preconditions, then constraints. Every sentence carries information; nothing is padded or redundant.

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 single-parameter, read-only fetch tool with no output schema, the description covers what it does, what it needs (daemon), what it accepts (.onion only), and what it returns (raw HTML). No significant gap remains 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 100% and there is a single parameter, so the schema already documents the URL field and its http/https form. The description only reinforces the .onion restriction already implied by the schema, adding no format or validation detail beyond it.

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 ('Fetch raw HTML from a .onion URL') plus the transport mechanism (Tor SOCKS5 proxy). Scope is narrow enough to distinguish it from siblings like tor_scrape_onion, tor_search_onion, and onion_lookup.

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 concrete preconditions ('Requires a running Tor daemon') and a hard input constraint ('Only .onion URLs are allowed'), which is real usage guidance. It stops short of naming which sibling to use for scraping/searching onions, so routing among the tor_* family is left to inference.

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