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

With no annotations, the description carries the behavioral burden and usefully discloses that the operation is unsigned and performs an approve for the exact amount followed by the back. However, it omits auth/login prerequisites, failure modes, and what the prepared unsigned payload should be used for.

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?

It is a single front-loaded sentence with no filler, packing purpose, execution sequence, and payout context efficiently. Slightly awkward phrasing such as 'a back' keeps it from being top-tier.

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?

Given no annotations and no output schema, the description explains the core prepare sequence but leaves the return/signing flow and prerequisites unstated. It is adequate for parameter selection but not fully complete for using the prepared output.

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 all four parameters are already documented in the schema. The description reinforces amount semantics with 'approve for the exact amount' and clarifies the entrant/spectator role, but adds little per-parameter 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?

Names Night Run, the specific action (prepare an unsigned back), the role (spectator), and the mechanics (approve exact amount then back). This distinguishes it from sibling prepare_night_run_enter/claim in substance, though those siblings are not explicitly named.

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 description implies usage by stating it is for backing an entrant as a spectator in Night Run, but it never gives explicit when-to-use guidance or contrasts this with prepare_night_run_enter, prepare_night_run_claim, or other prepare_* tools.

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