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

With no annotations, the description itself must convey safe behavior. 'List' clearly indicates a read/retrieval operation with no apparent mutation or side effects, which is useful transparency. However, it does not disclose whether the result is ordered, paginated, limited by default, or what fields the returned friends contain.

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 concise sentence with no filler or redundant phrasing. It is front-loaded with the action and the target resource. Nothing needs to be cut, and the brevity fits a simple list operation.

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 tool with no annotations, no output schema, and an undocumented parameter, the description does not provide enough context. It lacks information about what a 'friend' is, what the returned data looks like, how the optional limit behaves, or any ordering/pagination behavior. This leaves important gaps for an agent deciding whether to call this tool and how to interpret its result.

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 has one parameter, 'limit', with no description, and schema description coverage is 0%. The tool description does not mention the parameter or explain its meaning or default behavior. The agent has to infer from the parameter name alone that 'limit' may cap the number of returned friends.

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 uses a specific verb ('List') and a specific resource ('your agent's friends'), making the basic purpose clear. It is also distinguishable from the sibling tools, none of which are about listing friends. However, it does not elaborate on what qualifies as a 'friend' or what kind of representation is returned.

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?

No guidance is given about when to use this tool versus alternatives. There is no mention of prerequisites, context, or situations where another sibling tool would be more appropriate. The only implied usage is 'when you need a list of friends,' but no explicit direction is provided.

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