Canonical Host Check

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

The description goes well beyond the read-only/idempotent annotations by detailing the additional behavioral reports: HTTPS upgrade detection, permanent vs. temporary redirect classification, and identification of non-serving variants. It also clearly documents the returned structure (hop_count, redirect_statuses, findings), adding substantial transparency without contradicting the annotations.

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 well-structured and front-loaded: the core purpose appears in the first sentence, followed by concise bullet-style sections for additional reports, parameters, return payload, and an example. Every sentence contributes meaningful information with no filler or redundancy.

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?

Given the tool's moderate complexity, the description is remarkably complete: it explains what the tool does, what parameters are needed, what behavioral nuances are checked, the exact return structure, and provides a clear example. The provided annotations and schema also contribute, making this a fully self-contained tool description.

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 covers both parameters at 100% with descriptions. The description reinforces the site parameter by explicitly stating that 'www and scheme are ignored' (a practical clarification) and restates the response_format options and default. This adds modest but useful semantic depth beyond the schema.

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 identifies the tool's operation: fetching the four host/scheme variants (http/https × apex/www) and checking convergence on a single canonical URL. It uses a specific verb and resource combination that distinguishes it from siblings like redirect_trace and render_check.

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?

Provides clear context for when to use the tool (when homepage variants may be competing in the index, when checking canonical convergence) and includes a concrete example query. It does not explicitly name alternative tools or state when not to use it, but the use case is well implied.

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