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

With no annotations, the description carries the full burden and does well: it discloses that the call is free with no x402 challenge, that reports are reproducible from these criteria, and that tokenizer and corpus versions are pinned. It also gives the HTTP equivalent endpoint. It stops short of describing the response shape or size, which for a zero-parameter document fetch would have closed the loop.

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 resource and version pins are front-loaded, which is good, but the first sentence is a dense run-on packing six distinct artifacts, and the payment fact is stated three times in one clause ('no payment required', 'without payment', 'no x402 challenge; this tool is free'). Trimming that redundancy would sharpen it without losing information.

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 parameterless, annotation-free document-fetch tool with no output schema, the description supplies what an agent needs: what the criteria cover, why to read them first, that they cost nothing, and a direct HTTP fallback. Only the return format (single document vs. structured sections) is left unstated.

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 and the schema is an empty object, so there is nothing to disambiguate. Baseline of 4 applies; the description correctly implies no inputs are needed by framing the call as a direct read.

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 identifies a specific resource — the published criteria for the Split-Profile check (token-efficiency/v1, op split-profile, revision 1.2.0) — and enumerates its contents (input contract, serialisation, share grid, derivability self-check, pinned tokenizer, pinned corpus pin). It is clearly a spec/criteria retrieval tool, distinguishable from split_profile_check. It never uses an explicit verb like 'returns' or 'fetches', relying on 'Read these' to imply retrieval, which keeps it just short of a 5.

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?

'Read these before paying for a check — every report is reproducible from them' gives a clear call-ordering rule relative to the check tools. The payment note ('call directly without payment') further clarifies invocation context. It does not explicitly mention split_profile_precheck as the alternative entry point, so the sibling routing is implied rather than stated.

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