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

With no annotations, the description carries the behavioral burden itself: 'Read only' discloses the safety profile, and the listed fields communicate the return contents. It does not cover auth, rate limits, or pagination, but for a simple read-only listing it adds meaningful transparency.

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 tight sentences with no waste. The core purpose and return fields are front-loaded, followed by the sibling alternative and read-only note.

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, read-only list tool with no output schema or annotations, the description is nearly complete: it explains what is returned, that it is read-only, and where to go to enter a race. Only minor operational details are absent.

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 the single optional parameter 'n' is fully documented there. The description does not add syntax or default details for 'n', so it appropriately sits at the baseline when the schema does the heavy lifting.

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 description clearly identifies the resource as Night Run races and lists what each entry includes: stage, outcome, entrants, pot, and next stage timing. It is distinguishable from the sibling prepare_night_run_enter, though it does not explicitly start with a verb such as 'list'.

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?

It tells the agent to use prepare_night_run_enter to enter an open race, which is a useful sibling routing cue, and 'Read only' clarifies the operation type. It does not spell out when not to use this tool, so it falls short of full when/when-not guidance.

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