session_list

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

Annotations already cover readOnlyHint/idempotentHint/destructiveHint, so the description earns credit for what it adds: 'makes no model call', the ~5 min stale threshold behind the default, and the important visibility-only guarantee that sessions never affect oracle answers and oracles only see explicitly passed question/context. It does not disclose volume/truncation behavior, though limit=200 max suggests bounded output.

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?

Front-loaded with the 'COORDINATION — the operator dashboard' role, then scope, then defaults, then usage — a sensible ordering with no filler sentences. It is on the long side for a three-parameter list tool, and the read-only/model-call sentence partially restates the annotations.

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 enumerating the returned fields per entry. Combined with default behavior, stale threshold, and the visibility guarantee, an agent has everything needed to call and interpret 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 67% and the description meaningfully supplements it: it states the defaults (this project, active_only:true) in one place and explains the ~5 minute stale threshold that the schema's active_only description only gestures at ('recent heartbeat'). It says nothing about `limit`, so it does not fully close the coverage gap.

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?

Opens with a specific verb+resource ('Lists ask_fable sessions across instances on this machine') and names the concrete instances (opencode / Claude Code / salient windows). The scope statement plus the enumerated entry fields ('session key, agent_id, latest question, oracle, status, heartbeat age, turn count') makes it clearly distinct from ask_* siblings and from session_peek/session_stats without opening a schema.

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?

Gives a clear use context ('Use it to avoid duplicate work or watch the live fleet') and states which flag selects which mode: active_only:false for retained history, all_projects:true for the whole machine. It stops short of an explicit when-not-to-use or a named alternative among siblings (session_peek, session_stats, trace_list), so a 4 rather than a 5.

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