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

With no annotations, the description carries the full burden, and it does substantial work: it declares the data is cert-verified, that it is explicitly NOT a pop report, that it is free, updated daily, and committed on-chain. These are non-obvious traits that would otherwise mislead an agent. It still does not describe refresh lag beyond 'daily' or rate/quota behavior.

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?

Front-loaded with the core definition, then scope, then usage guidance in a clearly labeled sentence. It is somewhat parenthetical-heavy ('cert-verified — what is listed and pressing on price, NOT a pop report'), but every clause adds disambiguating information rather than filler.

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?

No output schema exists, so the description must convey what is returned, and it lists the returned aggregates (slab counts by grader, unique certs, cards covered, grader mix, active-30d counts) plus freshness and cost. An agent has enough to call it and interpret the result, though the exact shape of the totals is left qualitative.

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, so the schema has nothing to document and the 4 baseline applies. No parameter meaning is required or missing.

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 combination ('the observed graded-slab CENSUS as totals') and enumerates exactly what the totals are (unique certs, cards covered, grader mix, active-30d counts). It explicitly distinguishes itself from the per-card census at /api/v1/census, so an agent can route correctly.

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?

Provides an explicit 'Use this when' clause with two concrete conditions (sizing supply behind a grade; judging how thin a slab market is before trusting an ask) and points to the per-card alternative. It stops short of naming any of the listed sibling tools, so differentiation is by endpoint rather than by tool name.

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