util_open_graph

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

No annotations are provided, so the description carries the full burden of disclosure. It states the tool extracts fields but does not describe any behavioral traits such as network requests, failure modes, rate limits, or side effects. For an extraction tool that likely makes HTTP calls, this is a notable gap.

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 a single sentence with no unnecessary words, making it concise. However, it lacks structure such as a separate 'when to use' or 'return values' section, which could improve clarity without adding length.

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 absence of an output schema and the vague input parameter, the description does not sufficiently explain what the tool returns or how to structure the input. For a utility tool with a free-form parameter and no return type defined, more context is needed for agents to use it correctly.

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 has a single parameter 'arguments' of type object with no property descriptions (0% coverage). The description does not clarify what keys should be included (e.g., a 'url' field) or their formats. This leaves agents guessing how to properly invoke the tool.

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 identifies the tool's function: extracting Open Graph and Twitter card fields from a URL. The verb 'Extract' and resource 'Open Graph and Twitter card fields' are specific. However, it does not explicitly state that the input requires a URL, leaving some ambiguity for agents. It distinguishes from siblings by its unique focus on preview rendering.

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 phrase 'to preview how a URL will render in feeds and agents' provides context for when to use the tool, but it does not offer guidance on when not to use it or suggest alternative tools. The usage context is implied rather than explicitly stated.

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