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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds that the call is free and that the alerts are fact changes surfaced over time, which is useful context. However, it does not say what happens when no watches exist, whether results are truncated, or how alert recency is computed, so it goes slightly beyond annotations but does not add rich behavioral detail.

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?

It front-loads the free/scheduling cue and the alert categories are listed compactly in one sentence. The 'Input:' sentence partly repeats schema content, but the whole thing stays dense and readable with no filler.

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 zero-required-parameter read tool with a 100% schema and no output schema, the definition covers purpose, trigger, prerequisites, and the required credential forms. It is slightly under-specified only on return shape (how watches vs alerts are presented) and empty-watch behavior, which is a minor gap, not a blocking one.

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% and each parameter (token, api_key, since) is already documented in the schema with format hints (wt_..., fl_live_..., YYYY-MM-DD). The description restates those formats and the either-or relationship between token and api_key, which is mildly helpful but largely redundant. Baseline 3 is appropriate.

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 gives a specific verb (lists) and resource (watches and alerts), enumerates the alert categories (sanctions match, company status, name/address change, APK or recall change), and explicitly points to the originating siblings (watch_30_days or a key). An agent can distinguish this from watch_30_days, nl_apk_alert, and the screening tools without opening a schema.

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 states when to use it ('start of a session or on a schedule') and the precondition (the user has Factline watches from watch_30_days or a key). That is a clear context plus prerequisite, so nothing material is left to inference.

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