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 the returned data (each hop's status, target, timing) and the analysis performed (loop, mixed-content, and chain-length detection, with ≥3 hops flagged as an SEO warning). It still omits whether the trace is a read-only/HEAD-style fetch, what happens when the redirect limit is exceeded, and any rate or timeout behavior.

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?

Two sentences, front-loaded with the core verb and resource, followed by output detail and detection rules. No filler or redundant restatement of the name.

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 two-parameter read tool with no output schema and no annotations, the description covers purpose, return contents, and detection logic well enough to call it correctly. The main gap is the unexplained max_redirects parameter and the absence of any limit-exceeded behavior.

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 only 50%: url is documented in the schema and echoed in the description, but max_redirects is undocumented everywhere beyond its default/min/max bounds. The description discusses hop counting only in the SEO-warning context, so an agent gets no guidance on what max_redirects controls or how truncation is reported.

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 ("Trace the redirect chain for a URL") plus concrete output elements (every 3xx hop with status code, target, timing). That scope clearly separates it from sibling tools like check_http_status, check_url_expand, or check_resolve_url, which cover status/expansion/resolution rather than hop-by-hop chains.

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?

Usage is implied by the scope — you use it when you need the redirect path rather than a single status. However, it never says when to prefer this over check_http_status or check_url_expand, nor any prerequisites such as reachability or whether the URL must be absolute.

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