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

No annotations are provided, but the description fully discloses the tool's behavior: actively fetches the URL, slow (5-15s), shared daily budget, single-flight concurrency, never renders the page, low risk_score means 'not fully evaluated', and returned fields are attacker-authored. This exceeds typical disclosure expectations.

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?

Though long, the description is front-loaded with the essential purpose and every sentence adds critical operational or security context. It flows logically from purpose to usage to limitations to data-handling warnings, with no wasted words.

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 complex tool with no output schema and no annotations, the description covers purpose, when to use, performance, rate limits, response semantics (analysis_failures), and security handling. It is fully sufficient for an agent to decide and invoke the tool correctly.

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 the schema already describes the single url parameter including 'This URL WILL be contacted.' The description adds no new parameter-level semantics beyond restating the contact behavior, so the baseline of 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?

The description opens with 'ACTIVE deep analysis of a URL' and clearly contrasts with analyze_url (which NEVER contacts the target), listing concrete data sources (HTTP response, TLS certificate, RDAP, etc.) and the re-scoring engine. This precisely distinguishes it from the sibling tool.

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?

Explicitly states 'Use it only when analyze_url's passive signals are inconclusive and you need active evidence' and 'it is NOT a default first call.' It also warns against retry loops due to budget and concurrency limits, providing clear when-to-use and when-not-to-use guidance.

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