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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds non-obvious context the annotations cannot convey: output is market prices only with no recommendation, and weekly projections are gated behind a Pro tier. It does not mention rate limits or data freshness, keeping it short of 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?

Roughly two sentences, front-loaded with the user questions that trigger the tool, followed by output scope and the pricing/projection caveat. Dense but essentially waste-free; the 'Pro adds our weekly projection' clause is the only mildly promotional bit.

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 does the work of explaining the return shape — per-stat median strike-ladder prices plus anytime-TD price, compared on shared stats — and covers the 2–4 player constraint and the read-only, no-recommendation nature. Adequate for an agent to call it correctly, though error/edge behavior (unknown player names, fewer than 2) is unaddressed.

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 100% and there is a single 'players' parameter already documented with accepted forms in the schema. The description reinforces the 2–4 player limit and names example players, but adds no format or syntax detail beyond what the schema provides, so baseline 3 applies.

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 states a concrete verb+resource: it returns the median Kalshi market price for each stat plus anytime-TD price for 2–4 named players, compared on shared stats. It differentiates itself from projection-based tools via 'Market prices only — the call stays yours', though it never names the closest sibling, compare_players, so the boundary with that tool is left to inference.

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 gives a clear triggering context with quoted user questions ('should I start Nacua or Adams', 'who does the market like more this week') and a cardinality constraint (2–4 players). It does not state any exclusion or explicitly route the agent to a named alternative such as compare_players, so it stops short of a 5.

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