kin_session_exec

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

Annotations already declare destructiveHint=true, idempotentHint=false and openWorldHint=true, so the safety profile is covered. The description adds one genuinely useful behavioral fact – the can_execute capability requirement on the session – but says nothing about what a destructive run may modify, whether timeout truncation loses work, or what the tool does on failure.

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 short sentences with the core action front-loaded and the prerequisite second. No waste, though the prerequisite sentence is telegraphic to the point of being slightly ambiguous about which session must hold the capability.

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, destructive, open-world execution tool with no output schema, the description is thin: it omits what the command can affect, how output is returned once truncated, and any failure semantics. The can_execute prerequisite and the rich schema keep it at a minimum-viable level rather than inadequate.

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% and every parameter carries a description (argv 'no shell runs them', env refusal of loader/build keys, timeout clamping, per-stream truncation), so the schema does the heavy lifting. The description adds no parameter-level meaning beyond what is already documented.

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 set of verbs (build, test, run) against a concrete resource (this project with its toolchain), which is enough for an agent to distinguish it from the session-lifecycle siblings (kin_session_start/end/heartbeat) and from the mutation tool kin_mutate. It does not explicitly contrast with kin_mutate or the transaction tools, so it falls short of a 5.

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 only guidance is the precondition 'Session needs can_execute', which tells the agent what must be true before calling but not when to prefer this tool over kin_mutate or the transaction siblings. Usage is implied by the description's verbs rather than stated as when/when-not.

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