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

Annotations already establish read-only, idempotent, non-destructive, open-world behavior, so the bar is lower, yet the description still adds real context: the enforced rule that the score is 0–100 openness/activity/verifiability and explicitly NOT a safety, security, legitimacy, or returns grade, plus the self-reported-claims caveat and the required citation URL. It is docked one point because behavior is largely conveyed by enumerating payload fields rather than stating operational traits.

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?

Well front-loaded with USE WHEN / NOT FOR / RETURNS / RULE ENFORCED headings in a scannable order. Slightly penalized for redundancy: the return payload is described twice (prose RETURNS and the json key list), and 'Read-only' restates the annotation.

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, the description carries the full burden of describing the return payload, and it does: it enumerates every key (name, scale, components, tiers, provisional, not_in_score, computed, reproduce, dispute, caveat, url) and explains each section's content. Nothing an agent needs to call and use the tool is missing.

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?

There is one optional parameter (response_format) with 100% schema description coverage, so the schema already documents the enum and default. The description never mentions response_format or when to prefer markdown vs json, so it adds nothing beyond the schema — the correct baseline of 3.

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 (return the Sato Score methodology/rubric) and explicitly distinguishes itself from the two siblings that would otherwise look tempting: onchain_agent_get_resource for a single project's score and onchain_agent_get_listing_history for score movement. An agent can route correctly without opening any 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?

Explicit USE WHEN ('about to describe, apply or compare the Sato Score — or when asked how to tell whether a project is real, maintained or open') and NOT FOR clauses that name the exact alternative tools and parameters for each excluded case. Nothing is left to inference.

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