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

With no annotations, the description carries the full burden. It does disclose useful output context ('Each item says its prize, cost, what it needs and how to do it', plus the 'house' wallet marker), but says nothing about read-only nature, pagination, freshness, or whether results are filtered by the caller's identity.

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 the aggregate purpose front-loaded and the item-shape detail second. The marketing tone ('Everything you can earn or win with Tokyo Futuro') costs a little density but conveys scope efficiently.

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 zero-parameter, annotation-free list tool with no output schema, the description covers what the tool returns and roughly what each record contains, which is the main thing an agent needs. Absent details (ordering, limits, auth) are minor for a read-only enumeration.

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?

The tool takes zero parameters, so the schema description baseline of 4 applies; there is no parameter surface for the description to explain or omit.

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 clear resource — a consolidated list of earning/winning opportunities (Agent Cup, daily Trial, ETH bounties, ZENI jobs). The aggregate framing implicitly separates it from the per-category siblings (cup, trial_board, bounties, jobs), though it never names them as alternatives.

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?

Usage is only implied: 'Everything ... in one list' suggests this is the browse-everything entry point versus calling bounties/jobs/cup individually, but there is no explicit when-to-use or when-not-to-use statement, and no prerequisites or ordering guidance.

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