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

The description states it updates a watchlist but does not disclose whether the symbol list is replaced entirely or merged, or what happens if name or symbols are null. Annotations indicate it's a write (readOnlyHint=false) but not destructive (destructiveHint=false), yet the description adds no further behavioral 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 concise with a one-sentence summary followed by an Args list. It is front-loaded and free of fluff, but the Args block partially duplicates schema information and could be streamlined.

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 an update tool, the description should clarify that symbols replaces the entire list and note any permissions or existence requirements. The output schema may cover return values, but key behavioral details are missing, making the description incomplete for a mutation operation.

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 description adds brief semantic labels: 'The watchlist UUID' for watchlist_id, 'New name (optional)' for name, and 'Updated list of symbols (optional)' for symbols. This goes beyond the raw schema but lacks detail on symbol format, replacement behavior, or validation rules.

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 the tool updates a watchlist's name and/or symbols, identifying the specific action and resource. This distinguishes it from sibling tools like create_watchlist and list_watchlists, though it does not explicitly name an alternative.

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?

There is no guidance on when to use this tool versus alternatives, such as creating a new watchlist or deleting one. The description does not mention any prerequisites or conditions for updating, leaving the decision context unspecified.

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