server_info

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the bar is lower. The description still adds real value by disclosing what the response reveals about the server's operating envelope, notably whether writing is enabled and which sessions persist. It stops short of describing output shape, but an output schema exists.

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?

Front-loads the purpose, then the imperative 'Call this first.' The final clause mildly restates 'open sessions' from the first sentence, costing a little economy, but the elaboration on wasted turns earns its place.

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 no-param, read-only capability probe with an output schema, the description supplies everything needed: what it reports, when to call it, and why it matters. No gaps for an agent to fill.

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?

Zero parameters, so there is nothing to document and the baseline is 4. The description correctly implies the tool takes no arguments and returns a self-describing capability report.

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?

States a specific verb+resource pair (report the server's capabilities/limits/sessions) that is clearly distinct from the targeted siblings like list_processes and scan_value. An agent can tell this is the meta/overview tool without opening any schema.

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?

Gives explicit ordering guidance ('Call this first') and justifies it by naming the decisions it resolves (write-enabled, reachable processes, scan duration), which is exactly the when-to-use context an agent needs before touching the mutating siblings.

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