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

Annotations already declare readOnly/openWorld/idempotent, and the description goes well beyond them by revealing that matching is keyword/token-overlap based (pairing_unverified), that gross spreads do not model Kalshi fees, and what compatibility_codes mean. It also clearly defines edge cases like temporal_alignment_unknown and skipped_unclassified. This gives an agent realistic expectations about false positives and non-tradeable output.

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 long but front-loaded: the first sentence states the core purpose, then modes, then response safety fields. Some caveats repeat, such as temporal alignment warnings appearing in several forms, so it is not maximally tight. However, the density is largely justified by the absence of an output schema and the number of warning codes.

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 no output schema and a complex comparison tool, the description covers the input modes, response shape, matching limitations, skipped-class counters, fee treatment, and examples of using the shortcuts. An agent has enough information to invoke the tool and interpret its outputs without guessing.

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 complete, so the schema already documents each parameter. The description adds mode-level semantics: topic selects a pre-mapped shortcut, while kalshi_event_ticker and polymarket_event_slug override the mapped side, and both modes run the identical matcher. That relationship information is useful, though not deeply detailed beyond the schema.

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 opening sentence gives a specific verb and resource: it computes a cross-venue spread between Kalshi and Polymarket for the same resolving question. It clearly announces two operating modes and lists the pre-mapped topics. However, it does not explicitly distinguish itself from sibling tools such as polymarket_arbitrage or polymarket_edges, relying instead on the raw scope of the cross-venue comparison.

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 clear context on when to use the tool: for paired Kalshi/Polymarket events with equivalent bet shapes, using either a pre-mapped topic or an explicit ticker/slug pairing. It also warns that most pre-mapped topics currently return compatibility_warning and that pre-mapped does not mean tradeable. It does not explicitly name which sibling tools to use instead, so it falls short of the 5 standard.

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