Start a system design interview

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

Adds real side-effect disclosure the annotations cannot convey: the board is opened and the opening message is spoken aloud to the candidate, so the agent knows an audio/observable action occurs. The destructiveHint=true flag is not explained though — the description never says what starting a session destroys or overwrites (e.g. an in-progress session).

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?

A single sentence, front-loaded with the action and then the concrete effects, with zero filler. The parenthetical about audio delivery earns its place by flagging a non-obvious side effect.

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 6-parameter setup tool with an output-schema-free contract and annotations covering safety, the description covers the composite actions well. It omits what happens if a session is already running and whether the tool returns a session identifier or blocks awaiting the candidate, which are gaps but not crippling ones.

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 83%, so the schema already documents nearly every parameter, including examples for title, problem, and opening_message. The description only loosely maps its phrases to parameters ("problem statement", "timer") and adds no format or default detail beyond the schema; baseline 3 applies.

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?

Specific verb + resource ("Start a new interview session on the board") followed by an enumeration of exactly what it creates: problem statement, timer, phase, opened board, and opening message. This clearly separates it from siblings like open_board, set_phase, and say, which each do only one of these steps.

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 framing "Start a new interview session" plus the fact that it rolls board-open + phase/timer setup + opening line into one call implicitly tells the agent to use this instead of chaining those siblings individually. However, it never states when-not to use it (e.g. resuming an existing session) or names an alternative explicitly.

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