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

With no annotations, the description carries the full burden and does well: it discloses a mutation side effect (new addresses saved to a shared directory), a performance trait (slow when crawling, Tor-based fetching), a cost (3 credits/call), and a legal disclaimer. It does not cover rate limits, auth needs, or error behavior, so gaps remain.

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 the core action and side effect, then alternatives, then cost. The disclaimer/terms sentence is somewhat boilerplate but arguably warranted for this tool class; overall it is tight and well-ordered.

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?

No annotations and no output schema, yet the description covers purpose, persistence side effects, sibling routing, cost, and performance. The main remaining gap is the return value (what the call yields, e.g. counts or addresses found), which an output schema would normally supply.

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% (baseline 3), and the description adds meaning the schema lacks: crawling is 'one level deep' and records titles, clarifying depth semantics. It is slightly less precise than the schema on the crawl quantity limit but adds the depth constraint, so it earns above baseline.

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?

Specific verb ('Collect') plus a precisely scoped resource (v3 .onion addresses) and mechanism (from a seed page, optionally one level deep). It names the sibling onion_directory and how this tool differs from a plain listing, so an agent can distinguish it from onion_fetch/onion_directory without opening schemas.

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 states the use context (harvest from a clearnet directory or .onion seed page; optionally follow links) and routes the agent to onion_directory for listing. The 'Slow when crawling' note implies when to avoid the crawl, but there is no explicit exclusion versus onion_fetch for single-page retrieval.

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