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

With no annotations, the description carries the full burden and does so well: it discloses latency (30+ seconds), a per-call cost (3 credits), a network constraint (Tor only), a legal disclaimer, and what is returned. It stops short of auth requirements, failure modes, or rate-limit behavior, but the operational profile is unusually well conveyed.

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?

Front-loaded with purpose, then constraints, disclaimer, and cost in a compact block. Every sentence carries operational or legal weight, though the disclaimer sentence is comparatively verbose for its low selection value.

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 2-parameter fetch tool with no annotations and no output schema, the description covers return contents, latency, cost, and legality. The only real gap is the untoggleable, undocumented include_links parameter.

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 50%: url is documented in the schema, include_links has no description anywhere. The mention that links are returned loosely signals the default behavior but does not explain the include_links toggle, so the description only partially compensates for the coverage gap.

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?

A specific verb (fetch), resource (.onion page via Tor), and explicit scope (returned fields: title, readable text, links). The '.onion addresses only' clause separates it from clearnet siblings like scrape_page and crawl_site without opening either 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?

It names intended use cases (threat-intelligence, brand-protection, research) and an applicability constraint (.onion only), which implicitly routes the agent away from clearnet scrapers. However, it never explicitly names the alternative tool or states when to prefer scrape_page, so the routing is inferential rather than stated.

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