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

Annotations already declare the write-safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false), so the description is not the primary source. 'Free' adds a genuinely non-obvious cost/plan trait, but the description never warns that calling twice likely creates duplicates despite the non-idempotent annotation, nor says whether names must be unique.

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 short sentences, front-loaded with the action and with zero filler. It is efficient but borders on under-specified rather than concise.

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 trivial one-parameter create tool with annotations covering safety, this covers the essentials. It omits what is returned (no output schema) and whether the resulting watchlist identifier is needed for add_to_watchlist, which an agent likely needs next.

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% for the single 'name' parameter and documents the 1-120 character bounds, so the schema does the work. The description adds nothing about name uniqueness, trimming, or whether the name is the later lookup key.

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+resource ('Create a named account watchlist'), which is unambiguous on its own. It does not distinguish this tool from siblings such as list_watchlists, get_watchlist, or add_to_watchlist, so the agent gets no routing help.

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 create a new watchlist versus adding to an existing one (add_to_watchlist), and no mention of listing existing watchlists first. 'Free' implies a plan constraint but is not framed as usage guidance.

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