Hreflang Check

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows it's a safe read operation. The description adds valuable behavioral context by disclosing that with check_reciprocity=true it fetches each alternate URL, and explains the practical motivation (non-reciprocal hreflang is silently ignored by Google). It also outlines the return structure, making the tool's behavior fully transparent.

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 efficient. It leads with the core purpose, follows with an optional advanced behavior, and then lists Args, Returns, and an Example in a scannable format. Every sentence adds information, and nothing is redundant or verbose.

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 covers all essential aspects: what is validated, the optional reciprocity fetch, all three parameters, the expected return shape, and a usage example. The output schema is present, so the Returns summary suffices. Annotations cover safety and semantics, making this description contextually complete.

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 description coverage is 100%, so parameters are already well-documented in structured form. The description adds extra value by explaining check_reciprocity's purpose and consequence ('verify alternates link back'), clarifying the default for response_format, and providing an example that shows how to invoke the tool with meaningful arguments. This goes slightly beyond the schema but not dramatically, hence a 4.

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 a specific, actionable verb 'Validate' and precisely names the resource: a page's `<link rel='alternate' hreflang>` annotations. It enumerates concrete checks (BCP-47 validity, self-referencing entry, x-default fallback, duplicates) that clearly distinguish it from sibling SEO tools like meta_tags_check or structured_data_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?

The description gives clear context for when to use the tool (validating hreflang setup) and includes a concrete example query that illustrates the typical use case. However, it does not explicitly state when *not* to use it or name alternative sibling tools for other SEO checks, so it falls short of the highest bar for explicit usage guidance.

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