server_info

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

Annotations already declare readOnlyHint and idempotentHint, so the safety profile is covered. The description adds value beyond annotations by specifying exactly what data is retrieved (version, socket info, counts), which is helpful for the agent. It does not add extra behavioral details, but none are particularly needed for a simple read-only info tool.

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, front-loaded sentence with no filler words. It efficiently conveys the essential purposes without redundancy, earning a perfect score for conciseness.

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 simplicity (no parameters, read-only, output schema present), the description is fully adequate. It tells the agent what the tool does, and the output schema will handle return value details. There are no gaps in context for an agent to successfully invoke this tool.

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, so the schema is fully described and no parameter documentation is needed. The baseline for 0 parameters is 4, and the description correctly omits any parameter details because none exist.

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 'get' and clearly identifies the resource ('tmux server version, socket info, and counts'). It distinguishes this tool from siblings like list_sessions and get_pane_info by focusing on server-level metadata rather than session or pane data.

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 explicit usage guidance or alternative tools are mentioned. However, the description's clarity provides an implied usage: when an agent needs server-wide information like version or socket details. It does not state when not to use it, but the context of a no-parameter, read-only info tool makes its purpose fairly obvious.

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