session_explain_cell

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

No annotations are provided, so the description carries the full burden. It discloses the return structure and the one-level recursion limit well, implying a safe read operation. It doesn't mention error behavior for invalid cell names or missing sessions, leaving a small gap.

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 tight sentences, front-loaded with the purpose and followed by the recursion rule. Every clause carries information; no filler.

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?

There is no output schema, so the description must describe what is returned, and it does so precisely (role, op, args, upstream cells, values). Combined with the one-level recursion note, an agent has enough to call and iterate 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 description coverage is 0%, so the description must compensate for both parameters. It clarifies that 'cell' is a cell name that appears in dependency listings, which adds meaning, but sessionId is never explained and no format hints are given for either parameter.

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?

States a specific verb and resource ('Explain a cell's own derivation') and enumerates exactly what the explanation contains: role (free input vs computed), op and raw args, immediate upstream cells with values, and current value. This distinguishes it from session_get_cell, which would only return the value.

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?

Explicitly bounds the scope ('One level only') and tells the agent how to go deeper: re-invoke on a listed dependency's cell name. It doesn't explicitly compare against sibling tools like session_get_cell or session_list_cells, but the recursion guidance is clear and actionable.

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