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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false, but the description adds real context beyond them: XP is awarded on first completion, result verification is triggered, and the tool is gated to paid domains. The 'awards XP on first completion' line is consistent with idempotentHint=true. It doesn't say what verification entails or how to observe its outcome, which keeps it short of a 5.

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?

Three dense sentences with no filler: capability first, side effects second, preconditions and the safety constraint last. Every clause carries actionable information for an agent deciding whether to call it.

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 three-parameter mutation tool with no output schema, the description covers the mutation, its side effects, the paid-plan gate, and the consent requirement. An agent has enough to decide correctly whether and when to invoke 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 coverage is 100%, so all three parameters are already documented in the schema, including done=false un-ticking and the growth_plan origin of stepKey. The description reinforces the stepKey provenance but adds no new format or constraint details, so the 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?

States a specific verb (tick off / un-tick) and resource (a step of the domain's growth plan), and immediately distinguishes the operation from sibling complete_quest by naming the plan step. It also names where step keys originate (growth_plan), so an agent can locate the correct input without guessing.

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?

Explicitly covers when to use it (only after the work has actually been done), when not to use it (never without an explicit user request; not on free domains, which are read-only), and points at growth_plan for key discovery. That is a full when/when-not/alternative triad.

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