ck_set_session

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

Annotations declare non-read-only, idempotent, non-destructive behavior, so the safety bar is lower. The description adds real context by revealing what is being persisted (a credential that drives automatic token refresh) and the required provenance of the value; it does not discuss overwrite semantics or failure behavior, but the idempotentHint covers re-writes.

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?

Purpose and payoff are front-loaded in the first sentence, followed by concrete acquisition steps and a simpler alternative. The DevTools click-path is long but each clause is actionable, so little is wasted.

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 one-parameter credential-ingestion tool with no output schema, this covers the essential questions: what the value is, where to get it, why to provide it, and an easier substitute. Annotations carry the mutation/idempotency profile, so nothing critical is missing.

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 100% and the single parameter's description already states it is the full Cookie header containing CKAT/CKTRKID. The description repeats that plus a harvesting procedure, which is operationally useful but adds little semantic meaning beyond the schema.

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 ('Store a Credit Karma session') and adds the downstream purpose ('enable automatic token refresh'). An agent can distinguish this from sibling ck_forget_session and the read-oriented ck_* tools without opening the schema.

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?

Gives clear onboarding context (call this during setup) and names an alternative path (ContextMint Bridge extension that reads cookies automatically). It does not explicitly say when not to call it or point to ck_forget_session for teardown, so it falls short of full routing guidance.

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