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

Beyond the readOnlyHint and openWorldHint annotations, the description discloses the full response envelope (status field with ok, not_applicable, timeout, error), explains how to interpret each status (treat not_applicable as a finding, error as unknown), and mentions the per-hop timeout. This is rich behavioral context that exceeds annotation-level info.

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?

The description is compact and front-loaded with the core purpose, followed by use cases, timeout, and response format. Every sentence adds value—there is no fluff. The JSON response structure is embedded in a code block, making it immediately parsable, and the overall length is justified by the amount of behavioral detail.

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 read-only tool with one parameter and no output schema, the description covers purpose, usage, behavior, and error interpretation. It hints at the data structure ('one entry per hop with its status code and target') but does not specify the exact fields of the 'data' object. Given the absence of an output schema, this is a minor gap, but the description is otherwise complete enough for an agent to call 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?

The input schema already provides a detailed description of the 'domain' parameter (e.g., public domain, rejects IPs/ports/paths). The tool description adds the nuance that the domain is used with an https:// prefix, which is a minor semantic addition. Schema coverage is 100%, so the baseline of 3 is appropriate.

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 clearly states the action ('Trace the redirect chain'), the resource (from https://<domain>/), and the output (one entry per hop with status code and target, up to 10 hops). This is specific and distinguishes it from sibling tools like dossier_dns or dossier_headers, which serve different purposes.

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?

The description explicitly names two use cases: 'debug redirect loops' and 'confirm an HTTP to HTTPS or apex to www redirect.' It also notes a 5 s per hop timeout, which is a practical usage constraint. While it does not mention alternative tools for when not to use it, the given scenarios are clear and actionable.

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