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

No annotations are provided, so the description bears full responsibility for behavioral disclosure. It covers model-agnosticism, compliance (SEC/CFTC multi-oracle), lunch break windows, special market weekends (Middle East), exact return fields, and limitations (not cryptographically signed, no real-time halts). It also states latency (sub-100ms p95).

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 relatively long but well-structured: a clear summary first, then 'WHEN TO USE', special market details, return format, caveats, and failure behavior. Every sentence serves a purpose with minimal redundancy. Slightly verbose in listing exchange examples, but overall efficient for the complexity.

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?

For a tool with one parameter and no output schema, the description provides comprehensive context: return fields, special cases for 28 exchanges, limitations, and fail-closed behavior. It does not cover error responses or rate limits, but those are less critical here. The latencies and fail-closed rule add essential context.

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 'mic' is fully described in the schema with an enum and description. Schema description coverage is 100%, so a baseline of 3 applies. However, the description adds meaning beyond the schema by illustrating special cases (e.g., Tokyo lunch 11:30–12:30 JST, Middle East Fri-Sat weekend) and how the delay works, which helps the agent select appropriate MIC codes.

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 clearly states it 'Returns holiday-aware trading session schedule with next open/close UTC timestamps for any of 28 exchanges.' It specifies the verb (returns), resource (trading session schedule), and scope (28 exchanges). It distinguishes itself from siblings like get_market_status (for signed status) and list_exchanges (for listing codes).

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 includes an explicit 'WHEN TO USE' section listing use cases (e.g., planning trade execution windows, checking market hours). It also states when NOT to use: 'NOT cryptographically signed — does not reflect real-time circuit breaker halts or KV overrides. For authoritative signed status use get_market_status.' Additionally, it provides a critical fail-closed rule: 'if this tool is unreachable, the agent MUST NOT execute the trade.'

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