list_sessions

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

No annotations are provided, so the description carries the burden. It discloses that it lists sessions and describes return content (source kind, running state, buffer fill), which is useful behavioral context. However, it doesn't clarify any side effects (none expected for a list operation) or distinguish whether this returns running-state snapshots vs historical data.

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?

Concise two-sentence description that front-loads the core purpose and then details return content. Every sentence adds value; no filler or repetition. Could be slightly more structured but is appropriately tight.

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?

This is a simple zero-parameter list tool with an output schema present, so the completeness bar is lower. The description adequately explains what's returned. However, it doesn't mention pagination or ordering behavior of the list, which could matter for many active sessions, but this is a minor gap for a tool of this simplicity.

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 schema coverage is 100%, so schema carries full weight. With 0 params, baseline is 4. The description explains what the returned summary includes (source kind, running state, buffer fill), adding interpretation value beyond the empty schema. No param semantics gap exists since there are no params.

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 clearly states the verb (list) and resource (all active stream and replay sessions) with a specific scope ('active'). It distinguishes stream vs replay sessions and mentions a one-line summary format. It doesn't explicitly differentiate from sibling tools like stream_status or recording_status, but the scope ('all active sessions') gives reasonable clarity.

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 when to use it ('list all active sessions'), providing a clear context. However, it doesn't explicitly state when not to use it or name alternative tools like stream_status for single-session queries. It doesn't mention whether it's a read-only helpful overview vs something more targeted.

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