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

With no annotations, the description carries the full burden. It usefully discloses the overlap mechanism ('overlap between consecutive chunks preserves context') and the commercial terms (x402, $0.002/call in USDC on eip155:8453), which is real value. It omits behavioral limits: maximum input size, what happens when text is shorter than targetTokens, and any failure modes.

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 sentences, all doing work: operation, mechanism, and pricing. It is front-loaded with the core action. The inline pricing clause interrupts the flow slightly but is short and earns its place by exposing cost.

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?

There is no output schema and no annotations, so the description should describe the return shape, and it does not say whether the result is a list of strings, objects with offsets, or token counts. For a three-required-parameter tool that is otherwise well described, this is a meaningful remaining gap.

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 the baseline is 3, but the description adds genuine meaning beyond the terse schema labels: 'targetTokens' is framed as a token budget and 'overlapTokens' is explained as the mechanism that preserves context across splits. That interpretation is not available from 'Overlap tokens' alone.

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 and resource with meaningful scope modifiers: 'Split text into retrieval-friendly chunks with a token budget and sentence-aware boundaries.' An agent knows exactly what operation it performs. It does not, however, contrast itself with the adjacent dev_token_estimator or dev_text_extract siblings.

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 phrase 'the standard preparation step before embedding' gives implied context for when to reach for it, which is more than nothing. But there is no explicit when-not guidance, no statement about chunk-size selection, and no routing to alternatives such as dev_token_estimator.

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