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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), yet the description still adds real behavioral content: a 1–100 batch limit, per-item return fields with the exact shape of a null vote, and the api:read auth requirement. It doesn't say what happens to malformed or unknown ids, which is the only remaining gap.

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 statement and the id source, then the return shape, then the exclusion, then auth — a sensible order. The nested parenthetical in the second sentence is dense and slightly strains readability, but no sentence is 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?

With no output schema, the description supplies the return fields inline; with a single required parameter it explains the id source and limit; and it names a sibling for the adjacent question plus the auth scope. Nothing an agent needs to call this correctly 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?

Schema coverage is already 100%, so the baseline is 3; the description still adds meaning by saying where the ids come from (get_opportunities) and what each returned item maps to. It clarifies the pairing between the single input array and the per-id output rather than repeating the pattern constraint.

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?

The description opens with a specific verb+resource statement — the caller's own votes and saves on Today's Market opportunity cards — and names the exact id source (get_opportunities, mo_ + 32 hex). It is clearly separable from get_opportunities (card feed) and get_opportunity_detail (card content), so an agent can pick it without opening the 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?

It states the intended use (tell the user which cards in a feed they already voted on or saved) and explicitly carves out a neighbouring case it does NOT answer — Gambit tracking, routing to list_gambits. That is an explicit when-to-use plus a named alternative, leaving little to inference.

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