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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the tool is known to be safe. The description adds 'any watchlist you own or follow,' which clarifies scope but does not disclose additional behavioral traits like auth requirements or rate limits. It meets the baseline with annotations but adds little extra.

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 two sentences, front-loaded with the core purpose and a usage note. No wasted words or repetition of schema details.

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 simple read-only tool with two well-documented parameters and annotations covering safety, the description provides enough context in both purpose and usage. No output schema exists, but the intent is clear enough for an agent to invoke correctly without needing additional details.

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 100%, with both ticker and asset_type fully described. The description does not add any extra semantics beyond the schema, so it aligns with the baseline of 3 when the schema does the heavy lifting.

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 action ('check'), the resource ('watchlists'), and the scope ('specific ticker... you own or follow'). This distinguishes it from sibling tools like get_my_watchlists or add_to_watchlist by focusing on existence checking.

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 explicitly says 'Useful before adding it again,' which gives a clear context for when to use the tool. It does not explicitly name alternatives or exclusion criteria, but the purpose makes it obvious that it complements add_to_watchlist rather than replacing it.

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