webpage_metadata

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

With no annotations, the description carries the behavioral burden. It discloses the return format (structured JSON) and performance characteristic (cheaper than full load). It does not mention error handling or rate limits, but for a read-only metadata tool, this is sufficient and non-contradictory.

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 two sentences, front-loaded with the action and resource, followed by benefits and use cases. It lists many metadata types efficiently without being 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 low complexity (one parameter, no output schema), the description fully explains what it does and returns. It suffices for an agent to understand the tool's purpose and differentiate from siblings.

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 schema covers the single URL parameter 100%, and the description does not add meaning beyond the schema. It repeats that it fetches a URL but provides no additional constraints or format details, so baseline score 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?

Description clearly states it fetches a URL and extracts metadata, listing specific tags (title, OG, Twitter, etc.). It distinguishes from sibling tools like fetch_html by emphasizing it is cheaper than loading the full page, making the purpose specific and differentiated.

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 explicitly notes ideal use cases (link previews, SEO audits, content classification) and implies it is for metadata extraction rather than full page loading. However, it does not explicitly name alternative tools or state when not to use it, leaving a small gap.

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