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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds value beyond annotations by specifying the return fields (id, name, online status, default login user) and the connection to ssh_exec, which is useful given no output schema.

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 only two sentences, tightly packed with relevant information: what is listed, what fields are returned, and how to use the output. Every sentence earns its place and there is no redundant fluff.

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, read-only listing tool, the description covers the essential context: the scope of servers, the returned fields, and the follow-up action (ssh_exec with the id). No output schema exists, so the explicit return-field listing completes the picture.

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 the schema is empty with 100% coverage, so there are no parameter semantics to document. Per the baseline for zero-parameter tools, a score of 4 is appropriate; the description cannot add parameter meaning where none exists.

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 and resource: 'List the servers reachable through Termalin.' It also states the exact fields returned and connects to the sibling ssh_exec tool via 'Use the id with ssh_exec,' making its role distinct from the other siblings.

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 clearly implies when to use this tool: when you need to discover reachable servers and obtain an id for ssh_exec. It does not explicitly state exclusions or alternative list tools, but the context is clear enough for an agent to select it appropriately.

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