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

With no annotations, the description carries the full burden. It accurately indicates a read-only operation but does not disclose any side effects, authentication requirements, or potential limitations (e.g., rate limits, ordering, or whether the list is dynamic). For a simple list tool, this is adequate but not rich.

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?

A single sentence that is fully front-loaded with the action and object. No wasted words, and it conveys everything needed for the tool's primary function.

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 zero-parameter tool with no output schema, the description is reasonably complete. It does not specify the shape of the returned sites list, but given the simplicity and lack of any schema, an agent can infer the output. Minor gap: it could mention that the list is meant for use with the sibling tools, but that is not essential.

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 tool has zero parameters and schema description coverage is 100% (trivially). The description does not need to add parameter meaning, and the baseline of 4 applies because there are no parameters to document.

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 states a clear verb ('List'), a specific resource ('sites'), and a scope ('all available'), and it distinguishes itself from the siblings 'ask' and 'who' by being the only discovery/list operation. Even without explicit differentiation, the purpose is unambiguous.

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 implies usage as a precursor to querying sites but gives no explicit when-to-use or when-not-to-use guidance. It does not mention alternatives or prerequisites. For a zero-parameter discovery tool, this is acceptable but minimal; the context is clear enough for an agent to infer it should be called first.

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