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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description is consistent with them ('does not perform analysis, sign or charge'). Beyond the annotations it adds substantive context: cost (0.05 USDC on Base), the fact that no signing or charging occurs, and the exact return contents (canonical endpoint, supplied input, payment instructions). It does not say anything about request expiry or how to actually settle payment, which keeps it below a 5.

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?

Four short sentences, front-loaded with the analysis purpose followed by payment and scope constraints, with no filler. Each sentence carries distinct information (capability, cost, non-action, subtype restriction). Slightly more compact phrasing could fold the payment and 'does not sign or charge' statements together.

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 the description usefully enumerates what is returned, so the return side is adequately covered. The main gap is the four undocumented numeric parameters, which are central to this tool's correctness. For a prepare-only tool with safety annotations, the flow explanation is good, but parameter meaning remains incomplete.

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 0% for the four required parameters, so the description must carry the burden, and it largely does not. The phrases 'duplicate nodes' and 'short edges' loosely hint at nearNodeMm and minSegmentMm, and the 'Mm' suffix implies millimetre units, but closeGapMm is never explained and no threshold semantics or valid ranges are given. An agent still has to guess what each numeric threshold controls.

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+resource ('Find duplicate nodes and short edges in prepared vector paths') and adds a scoping clause ('Checks explicit polylines, not unconverted curved artwork') that implicitly separates it from the sibling prepare_native_vector_health. It also makes clear the tool only prepares a request rather than running the analysis, so an agent can tell what it does. It never names the native sibling outright, so the differentiation is inferential rather than explicit.

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 description makes the two-step flow clear: this tool does not perform analysis, sign or charge, but returns the canonical endpoint and payment instructions, which tells the agent this is a preparatory step in a paid HTTP workflow. The 'explicit polylines, not unconverted curved artwork' clause gives a negative condition for when not to use it. It stops short of explicitly naming sibling alternatives for those excluded cases.

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