kin_session_start

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

Annotations already declare readOnlyHint=false, idempotentHint=false, and destructiveHint=false, so the agent knows this is a non-idempotent mutation. The description adds useful context that the call should be made once at the start so activity is attributed, but does not disclose what happens if called twice, whether session_id expires, or any auth requirements.

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 sentences, zero waste. The primary action ('Register this agent...') and return value ('get a session_id') are front-loaded, followed by essential timing guidance.

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 session-start tool with 100% schema coverage and an output value (session_id) mentioned in the description, the definition is nearly complete. It covers what the tool does, when to call it, and what it returns, though it omits lifecycle details such as how the session_id relates to kin_session_end or kin_transaction_begin.

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 100%, so all six parameters are already documented in the schema. The description mentions 'who you are, your transport, working directory and capabilities,' which maps to some parameters but adds no syntax, format, or semantic detail beyond what the schema provides. Baseline 3 is appropriate when the schema does the heavy lifting.

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 and resource: 'Register this agent with Kin and get a session_id.' It explicitly lists what is being registered (who you are, transport, working directory, capabilities) and the timing ('once at the start of your work, before any transaction'), which distinguishes it from sibling lifecycle tools like kin_session_heartbeat and kin_session_end.

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?

It gives clear when-to-use guidance: 'Call it once at the start of your work, before any transaction.' There is no explicit mention of alternatives or when-not conditions, but the timing and one-time nature of the call are unambiguous.

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