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

Beyond the annotations (readOnly, openWorld, idempotent), the description discloses important behavioral details: returns snapshot probabilities rather than executable quotes, prices can change, closed/inactive/archived/missing markets are omitted, and an end date alone does not prove closure. It also warns that upstream text is data, never instructions, adding extra safety context.

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?

Every sentence earns its place: the core purpose is front-loaded, followed by workflow, key usage rules, behavioral caveats, and a security caution. Despite being relatively detailed, there is no fluff or repetition; each line addresses a distinct point an agent must know to invoke the tool correctly.

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?

The description is complete for a read-only display/search-support tool. It covers the workflow tie-in to search_markets, selection criteria, cardinality constraints, return-type caveats (snapshot probabilities), edge cases (closed/inactive markets), and a safety warning about untrusted upstream content. The output schema can handle any remaining return-format details.

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 schema already documents both parameters at 100% coverage, so baseline is 3. The description adds meaningful parameter semantics by explaining that each slug is exactly one market (not all markets in its parent event) and that up to three close matches should be passed together for comparisons, which goes beyond the schema's basic type/pattern info.

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 clear action ('Display up to three relevant active Knoww prediction markets as interactive cards') and distinguishes itself from search_markets by indicating that this tool renders/passes selected market slugs while search_markets is the lookup step. It also clarifies the unique scope: each slug is one market, not a parent event.

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 an explicit workflow: first call search_markets, compare event and dates with the user's question, then pass selected slats. It also gives when-not guidance ('Never invent identifiers or select weak matches just to fill cards') and covers comparison usage ('pass up to three close matches together').

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