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

No annotations exist, so the description carries the full burden. It does disclose a genuinely useful behavioral fact — cost of $0.005 per call paid in USDC on Base — but says nothing about the return shape (presumably an array of sentence strings), length limits on the output, or how ambiguous delimiters are treated.

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?

A single sentence that front-loads the action and the handled characters, then appends cost. No filler at all.

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 annotations and no output schema, the description should state what comes back from a split (list of strings? single string?) and whether empty input is an error. For a two-parameter tool this is close to adequate, but the return contract is left entirely 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?

Schema description coverage is 100% and the text parameter documents the 100000-character limit, so the schema does the work. The description adds nothing about the parameters, and the example options value ({"digits":"ascii"}) is only in the schema, so baseline 3 applies.

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?

Specific verb+resource ('Split Persian text into sentences') with the delimiter set named, which makes the operation unambiguous against siblings like fa_normalize or fa_stripHtml. No sibling is explicitly named as an alternative, but none competes for this task.

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 by the operation itself — an agent can infer when splitting is wanted, but there is no explicit when-to-use, when-not, or comparison to a sibling tool. The price note helps with cost decisions but is not usage guidance.

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