Create watchlist

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

Annotations already declare readOnlyHint=false, idempotentHint=false, and openWorldHint=true, so the agent knows this is a non-idempotent write with external effects. The description adds that it returns the new id, which helps with follow-up calls, but doesn't state failure modes, naming constraints (beyond schema maxLength), or the effect of duplicate names.

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?

Two tight sentences: first states the action and optional prefill, second states the return and where to read next. No filler, front-loaded with the core operation.

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 3-parameter creation tool with no output schema, the description covers purpose, optional parameters, return value, and next step. Missing only minor behavioral details like duplicate-name handling or default market behavior, which are partially covered by schema defaults.

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 only 33%, so the description must compensate. It clarifies that 'symbols' accepts either ticker symbols or Thndr asset ids, adding meaning beyond the schema's brief item description. The 'name' and 'market' parameters are adequately covered by the schema. The description doesn't explicitly explain the 'market' enum values, but the schema does.

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?

States a specific verb (Creates) and resource (watchlist) with scope detail about what it can be pre-filled with (tickers or asset ids). Clearly distinguishes from siblings like get_watchlist and edit_watchlist by naming one as the read counterpart.

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?

Explicitly names get_watchlist as the read alternative and implies this is the creation path. Doesn't cover when not to use it (e.g., if a watchlist already exists) or prerequisites, but the routing guidance is clear.

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