start_session

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

No annotations, so the description carries the burden. It usefully discloses the return payload (session_id, working method, first entry's SOP), but says nothing about the stateful side effects of creating a session, whether it can be called twice, or what happens on duplicate invocation.

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?

One lead sentence covering purpose and return, then a tight per-parameter gloss with no filler. Front-loaded and every clause carries 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 stateful session-creating tool with no annotations and no output schema, the description covers inputs and returns but omits the life cycle: which sibling to call next, whether the session expires, or how add_entries/end_session relate to it.

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 only 25% — request and end_goal are entirely undocumented in the schema — and the description compensates by defining all four parameters, including that entries must be ordered and derived backward from end_goal and what task_conditions should enumerate. It adds real meaning the schema lacks.

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 ("Start a design session") and adds what comes back (session_id, working method, first entry's SOP). It does not name any sibling tool, but the start/end lineage against end_session and the read-only siblings is inferable from the verb.

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?

Usage is only implied: a tool that mints a session_id is obviously the entry point before current_step, complete_step, or submit_plan, but the description never says so or names when not to use it (e.g., use add_entries to extend an existing session).

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