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

Goes well beyond the annotations (readOnlyHint=false, openWorldHint=true) by disclosing the monetary cost ('this SPENDS coins'), the quote-locking mechanism via expected_total, and that results are reviewed only after the run finishes. These are exactly the behavioral traits an agent needs before invoking a spend-capable mutation.

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?

Four tight sentences, no filler, and the cost warning plus quote-locking instruction are front-loaded right after the core action. Every sentence contributes distinct information an agent must act on.

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 mutation tool with no output schema, it covers the cost model, the safeguard, and the alternate cut_only path, and notes results surface after the run completes. It does not address reversibility even though a sibling undo_turn exists, which is a minor omission.

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?

With only 40% schema description coverage, the description carries real weight: it explains run:true semantics, that expected_total should equal the turn's estimate.total_coins, and what cut_only does. turn_id and funding rely on the schema, leaving one gap, but the added meaning is substantial.

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 ('Apply a turn's proposed canvas') and clarifies that the action splits into three distinct behaviors: the base apply, the optional run start, and the separate cut_only path. This lets an agent distinguish it from siblings like start_run, interject_turn, and undo_turn without opening schemas.

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 conditional guidance: use run:true to start the run, cut_only:true for a cut_proposal held for review, and always pass expected_total when spending. It lacks explicit routing against named alternatives such as estimate_run or start_run, so it stops short of full when-not guidance.

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