Quick sanity-check a model

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

Annotations only declare readOnlyHint=false, openWorldHint=true, idempotentHint=false and destructiveHint=false; the description goes well beyond that by disclosing that calls are real and paid, that a result is written to disk, which provider is billed for an 'anthropic:' ref, which provider is the default, and that there is no confirmation step. These are exactly the operational facts an agent needs before triggering a spend.

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?

Short declarative sentences, front-loaded with the defining scope ('one model, one scenario, one judge') and the cost/write warning immediately after. No filler, and the sibling pointer is correctly placed last as an escape hatch.

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?

With an output schema present, return values need no explanation, and the description covers the non-obvious risks: paid calls, disk writes, billing routing, defaults, and the absence of a confirm form. Only a stated alternative for heavier runs is missing, which is minor.

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 the schema already documents model refs, @level suffixes, judge shape, turns range, and plugin defaults in more detail than the description. The description restates 'Optional judge' and 'turns sets 1-10 turns' but adds no syntax or fallback meaning beyond the schema, 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?

The opening 'The cheap check: one model, one scenario, one judge' states a concrete verb (check/test) and scopes the resource tightly, and the closing pointer to tournament_options for bench/scenario IDs separates it from a sibling by function. An agent can distinguish this from tournament_plan_run or tournament_evaluate without opening any 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?

'The cheap check' frames the intended use case (quick sanity check rather than a full run), and it explicitly routes to tournament_options when bench or scenario IDs are needed. It stops short of naming a when-not condition or pointing at the alternative for deeper runs, so it earns a 4 rather than a 5.

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