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

No annotations are supplied, so the description carries the full burden and does well: it discloses the rate limit, the exact return contents (verdict line, token count, excess figure) and the critical negative fact that no shaped payload is returned. It does not state what a refusal looks like or whether the counter decrements on invalid input, leaving some mutation/limit semantics unstated.

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?

Three tight sentences with the key constraint, the return contents, and the paid alternative in that order. Some phrasing is jargon-heavy ('headline payload-budget pre-check', 'pass caller') and costs a moment of parsing, but nothing is wasted.

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 no output schema and no annotations, the description supplies both the return shape and the rate-limit safety context, which is what an agent needs to call this correctly. Only edge behavior (refusals, allowance accounting on failures) is left implicit.

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 coverage is 100%, so baseline is 3; the description adds meaning by tying 'caller' to the free-allowance key and framing budget_tokens against the pinned cl100k_base tokenizer used for counting. It still says nothing about how keep_fields or reserve_tokens interact with a pre-check that returns no shaped 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 (pre-check) and resource (payload token budget) with explicit scope: one submitted payload, headline verdict only. It explicitly contrasts itself with token_efficiency_budget (the paid full report), so an agent can distinguish the two without opening either 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?

Clear routing: use this for a free check, use token_efficiency_budget for the signed report with shaped payload and drop receipt, and the free allowance is bounded at 100/day per wallet. It does not address when to pick other adjacent siblings such as token_efficiency_criteria or tokens_score, so the exclusion set is incomplete.

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