domain_info

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 clearly implies a read-only lookup ('Look up stored knowledge') and details the information returned. Doesn't cover missing-domain behavior, but the operation's nature is 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?

Three sentences front-load the purpose, list the return values, and point to an alternative. Every sentence earns its place with no filler.

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?

For a simple one-parameter lookup tool with an output schema, the description sufficiently covers functionality and returns. The cross-reference to add_domain adds context. Minor edge cases are not essential here.

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 0%, so the description must compensate. It implies the 'domain' parameter is the target domain, but gives no format or example (e.g., bare domain vs full URL), leaving ambiguity.

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 starts with a specific verb+resource: 'Look up stored knowledge about a paywall domain.' It enumerates the returned data (status, notes, success rates, best archive order), which clearly distinguishes it from sibling tools like search_archives or add_domain.

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: it's for looking up stored metadata about a domain. Explicitly names add_domain as the alternative for registering new domains. Doesn't exclude search_archives or get_from_archive, but the scope is self-evident.

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