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

Annotations already declare readOnly, idempotent, non-destructive and open-world behavior, so safety is covered. The description adds useful provenance (Proof API) and the returned field set, but says nothing about volume, ordering, or whether the result is paginated — which matters since it claims to return ALL markets.

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 dense sentence with the resource front-loaded and the returned fields packed into a compact list. No waste, though the telegraphic phrasing leaves the key 'all markets, optionally filtered' nuance unstated.

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?

For a simple read-only list tool with no output schema, the description covers the source and the fields returned, and annotations carry the safety profile. Minor gaps remain around pagination, ordering, and the existence of the status filter, but an agent could call this correctly as-is.

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?

One optional parameter with 0% schema description coverage; the enum values are self-explanatory but the description never mentions that a status filter exists. Worse, 'All Vitro markets' can read as implying an unfiltered result set, so the description does not compensate for the coverage gap.

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?

Names the specific resource (Vitro markets) and enumerates the payload it returns (status, expiry, caps, totals, price), so an agent knows exactly what comes back. Sibling differentiation is only implicit — it never states how it differs from get_market or list_series, though the plural name conveys listing.

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?

No when-to-use, when-not-to-use, or alternative routing is given. The agent must infer that this is the discovery tool versus get_market for a single market, and nothing tells it whether filtering by status is preferred over listing everything and filtering client-side.

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