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

Annotations already declare readOnlyHint, and the description adds meaningful behavioral context: it explains the tiered access (free single largest gap, email top 3, Pro whole board), the output fields, and even points to a public track record URL. This goes beyond the annotations without contradicting them, though it does not elaborate on exact response formatting or error handling.

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?

The description is front-loaded with the core function and output, then moves through tiering, example queries, and track record. Each sentence adds value, but the track-record sentence makes it slightly longer than necessary, so it earns a 4 rather than a 5.

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?

Given a single optional parameter and no output schema, the description covers the core behavior, limitations (free/email/Pro tiers), and even provides a track-record link for credibility. It could be more detailed about response structure or edge cases, but for the simplicity of the tool, it is quite complete.

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 only parameter, minGap, is fully described in the schema (default, accepted formats). The description does not add any additional parameter-level guidance, so with 100% schema coverage, the baseline score of 3 is appropriate.

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 precise verb and scope: 'Scan for cross-platform price gaps between Kalshi and Polymarket on the same sports contract (NBA, NHL, MLB, World Cup).' It clearly lists the outputs (implied probability gap, WATCH/ARB signal, cheaper venue) and even includes example user queries, making it unambiguous and distinct from sibling tools like scan_mispricings.

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?

The description gives explicit example use cases ('Use for "where is the arbitrage", "cross-platform price gaps", "Kalshi vs Polymarket mispricing"') that tell the agent when to invoke this tool. However, it does not explicitly mention alternative tools or when not to use it, stopping short of a full usage guideline.

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