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

No annotations are provided, so the description carries the full burden and does so: it discloses side-effect profile (read-only), cost (free), auth requirements (none), and rate-limit impact (none). It also enumerates the response keys, which a zero-param tool with no output schema otherwise leaves entirely opaque.

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?

The payload contents are front-loaded in the first clause, the disambiguation against sibling tools follows immediately, and the access guarantees and return keys close it out. Two sentences, no filler, and the parenthetical exclusion is placed exactly where the ambiguity would arise.

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 zero parameters and no output schema, the description supplies everything an agent needs: what comes back (field-by-field), that it costs nothing, needs no credentials, and cannot disturb anything. There is no meaningful gap left for a caller to guess at.

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 no parameters, so there is nothing for the description to disambiguate and the baseline is 4. It correctly spends no words on inputs and instead redirects effort to the return payload.

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 (list) and enumerates the exact resources returned: symbols, timeframes, per-call USDC tool pricing, and payment network. It explicitly pre-empts the obvious confusion with sibling tools by clarifying 'not asset prices — call get_signal_bias etc. for those', so an agent can distinguish this discovery tool from the market-data siblings 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?

Names the alternative (get_signal_bias 'etc.') and the condition that selects it (you want asset prices rather than tool prices). It also states the access conditions — free, read-only, no auth, no extra rate limit — which tells the agent it can call this unconditionally, with no prerequisites to satisfy first.

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