session_list

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

No annotations are provided, so the description carries some burden. It says 'List active sessions' which implies a read-only operation, but does not detail any behavioral traits beyond that, such as what 'state' means or whether the result is a full snapshot. No contradictions, but limited disclosure.

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, front-loaded with the verb and rescope. No wasted words. It perfectly balances brevity with clarity.

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 zero parameters and no output schema, the description adequately communicates the tool's purpose. It doesn't explain the output format, but for a simple list operation, the description is sufficient. Could detail different states, but not critical.

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 parameter semantics are trivially covered by the schema. The description adds meaning by specifying what information is returned (sessions, languages, state), which enriches the semantics beyond the empty schema.

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 resource ('active sessions'), clearly stating what the tool does. It directly states the session scope which is distinct from read/run/write session tools, though it doesn't explicitly mention filtering.

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 the use case: checking active sessions and their languages/state. While there are many session-related sibling tools, the description clearly indicates this is for listing/metadata, but doesn't explicitly state when not to use it (e.g., for getting content use session_read_file).

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