Get session detail

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

The description explicitly lists returned fields (title, cwd, status, todos, message count) which goes beyond the readOnlyHint annotation. It also states 'Read-only,' consistent with annotations. No contradiction or missing behavioral detail like error cases, but for a simple read operation this is sufficient.

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?

Two sentences with no fluff. The main purpose is front-loaded, followed immediately by the usage prerequisite. Every word earns its place; it is concise while packed with necessary information.

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 read-only tool with 2 parameters, no output schema, and no nested objects, the description covers the returned data, the source of parameters, and the read-only nature. Nothing critical is missing for an agent to call it correctly.

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?

Schema coverage is 100% with descriptions for both agent and session_id. The description adds value by clarifying that these come from list_sessions/search_sessions results, giving origin context that helps the agent know exactly what values to pass.

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 a specific action: 'Get a single session's title, cwd, status, todos, and message count.' This differentiates it from sibling tools like list_sessions (listing) and get_transcript (transcript). It also specifies the exact data returned.

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?

It provides a direct prerequisite: 'Use the agent and id fields from a list_sessions/search_sessions result.' This implies a workflow but does not explicitly mention when not to use alternatives like get_transcript. Still, it gives clear context on how to obtain the required parameters.

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