list_sessions

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states the tool returns 'a summary of all currently active sessions' but doesn't specify what 'basic information' or 'summary' includes, whether there are pagination limits, rate limits, authentication requirements, or what 'active' means in this context. The description provides minimal behavioral context beyond the basic operation.

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 appropriately concise with two clear sentences that directly state the tool's function. The first sentence establishes the core purpose, and the second reinforces it without redundancy. There's no wasted language, though it could be slightly more front-loaded by combining the two sentences.

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 (0 parameters, no output schema, no annotations), the description is minimally adequate. It explains what the tool does at a high level but lacks details about the return format, what constitutes 'active' sessions, or how this differs from related session management tools. For a read-only listing operation, more context about the output would be helpful since there's no output schema.

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 0 parameters with 100% schema description coverage, so the baseline is 4. The description appropriately doesn't discuss parameters since none exist, and it correctly focuses on what the tool does rather than trying to explain non-existent inputs.

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 clearly states the verb ('List') and resource ('all active sessions and their basic information'), making the tool's purpose explicit. It distinguishes from siblings like 'get_session_status' by focusing on listing all active sessions rather than checking a specific session. However, it doesn't explicitly differentiate from other list-like operations that might exist in the broader context.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention when to prefer 'list_sessions' over 'get_session_status' for checking individual sessions, or how it relates to session creation/deletion tools. There's no context about prerequisites, timing, or exclusion criteria.

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