check_hreflang

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

No annotations are provided, so the description carries the full burden. It discloses credit cost (10 credits) and the requirement for VISIBLYAI_API_KEY, plus hints to check balance via get_account_info. However, it does not describe error handling, response format, or side effects beyond validation.

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 extremely concise with two sentences, front-loading the main purpose and then adding essential behavioral info (credits, API key). Every sentence earns its place with no 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 simple tool (one parameter, output schema exists), the description covers the core functionality, cost, and prerequisites. It could be slightly improved by adding context about what constitutes a 'valid' hreflang, but overall it is sufficient for the agent to understand the tool's role.

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 for the single parameter 'url' is 0%, and the description does not add any meaning about the parameter (e.g., expected format, whether it must be absolute, etc.). The tool's name implies it's a URL but nothing beyond the schema's minimal 'type: string' and 'required'.

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 tool validates hreflang annotations and lists specific aspects (x-default, language codes, broken targets, bidirectional linking). It distinguishes from sibling tools like check_links and analyze_url_structure which focus on different aspects.

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 implicitly suggests usage when validating hreflang tags but does not provide explicit when-to-use or when-not-to-use guidance, nor does it compare with alternatives. The name alone implies context but lacks explicit direction.

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