List agent sessions

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

The annotation readOnlyHint=true already discloses the read-only nature, and the description redundantly states 'Read-only.' The description adds a bit of behavioral context by describing the output fields (running, topic, status), but it does not disclose potential limitations like pagination, error behavior, or rate limits. Since the annotation covers the safety profile, the description adds minimal extra value.

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, well-structured sentence that front-loads the verb and resource, then provides the scope and return info. There is no redundancy or filler—every word 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?

With no output schema, the description compensates by stating what fields are returned (running, topic, status), which is helpful. It does not explicitly mention pagination or limit behavior, but the schema already defines 'limit' as 'Max sessions to return, per adapter.' The description is adequately complete for a listing operation.

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 schema description coverage is 100%, so all 4 parameters (cwd, agent, limit, running_only) are already well-documented in the schema. The tool description does not add any semantic meaning beyond what the schema provides, so it meets the baseline of 3 without further contribution.

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 states a specific verb ('List'), a precise resource ('coding-agent sessions on this machine'), and enumerates the agent types (Claude Code, OpenCode, Cursor, Codex). It also clarifies what is returned ('what's running, its topic, and its status'), which distinguishes it from sibling tools like get_session that fetch a single session. This is clear and specific.

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 usage (e.g., use this to get a broad overview of sessions on this machine) but does not explicitly state when to prefer this over search_sessions or get_session. There is no mention of alternatives or when not to use it, leaving some inference to the agent.

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