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

Beyond the readOnlyHint, openWorldHint, and idempotentHint annotations, the description adds critical behavioral caveats: a 24-hour window and that data is paper-trading only, not real money. It also discloses the output shape and the existence of `_next_actions`, which is valuable operational 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?

The description is longer than average but every section earns its place, with clear labels like 'Purpose', 'Triggers', 'When to call', 'Prerequisites', 'Next steps', 'Caveats', and 'Output'. It is front-loaded with the essential purpose and uses efficient formatting; no filler or redundant repetition.

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 the modest complexity of one parameter, the description is fully complete: it covers purpose, invocation triggers, usage position relative to other tools, prerequisites, caveats, and a breakdown of the output fields. The presence of an output schema is supplemented, not replaced, by a clear enumeration of the returned full_data structure.

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?

Even though the input schema has no parameter description and 0% schema coverage, the description fully documents the `market` parameter, including its default of 'all' and the allowed values 'crypto', 'kr_stock', and 'us_stock'. This compensates completely for the schema gap and adds practical meaning.

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 'Purpose: Single-call market overview' and enumerates a specific, concrete bundle: macro regime, top strong signals, yesterday's paper-trading outcomes, active forecast count, and narrative. This clearly distinguishes it from the many sibling tools that each handle one narrower concern.

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 explicitly says 'Use this as the first call when answering "how is the market today?"' and provides a rich set of trigger phrases and when-to-call scenarios. It also advises preferring this over answering from training data, and names next-step tools for deeper dives.

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