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

Annotations cover the safety profile (readOnly, idempotent, non-destructive), and the description still adds real behavioral substance: no login required, a hard 15-hop cap, the exact response shape, and the critical 'unmeasured' caveat that a silent port 80 is not the same as no upgrade.

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 action, then return shape, then semantics, then caller intents — a logical order. It runs long in a single paragraph and the httpUpgrade taxonomy is dense, but each clause carries disambiguating 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?

There is no output schema, yet the description enumerates every returned field and explains the httpUpgrade states, so an agent knows exactly what comes back. Auth requirements are stated and the measurement caveat is covered — nothing essential is missing.

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?

Only one parameter and schema coverage is 100%, so the schema already carries the meaning. The description adds nothing about domain formatting beyond what the schema example provides, so the baseline 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?

Specific verb 'Trace' plus a precise resource: the full HTTP redirect chain for a domain. The scope (up to 15 hops, each URL and status code) plus the dual chain/httpChain framing makes it unmistakable versus siblings like check_ssl or check_security_headers.

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?

Enumerates concrete caller intents — redirect chains, 'why does my site redirect', SEO redirect issues, mixed-content redirects, forced HTTPS, final landing URL. It gives strong for-when guidance but never names a sibling alternative or a when-not-to-use case.

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