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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context beyond that: it explains that findings marked seed:true are NOT new launches (first check seeds the board), that it returns stored results of past runs, and explicitly contrasts with the tool that triggers checks. This enriches the agent's understanding of what the tool does and how results should be interpreted, without contradicting the annotations.

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 longer than typical but every sentence earns its place: it states the purpose, describes the output, gives usage examples, clarifies the seed behavior, and distinguishes from sibling tools all in a compact block. Information is front-loaded with the core purpose first, and the seed clarification is placed where it naturally matters. It's structured and not wasteful.

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?

There is no output schema, so the description must explain what the tool returns, which it does (new ads, watch state, seed flag meaning). It covers the read-only nature, the distinction from running a check, and the context of when findings are genuine vs. seeds. For a read tool with no side effects, this is nearly complete; the only minor gap is that it doesn't describe pagination or ordering, but given the sibling context and the read-only annotation, this is not critical.

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 description coverage is 100% — both 'limit' and 'competitor' have detailed descriptions including defaults, max values, and semantics. The description does not add any parameter-specific information beyond what the schema already provides; it only mentions the limit default implicitly via the schema. Since the schema carries the full weight, a 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 opens with a specific verb ('Read') and a clear resource ('the standing COMPETITOR WATCH'), and immediately states what it returns: new ads per watched brand plus the watch's own state. It also explicitly contrasts itself with set_competitor_watch (which triggers a run) and save_to_swipefile (for saving), so an agent can distinguish it from siblings without opening schemas.

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 gives explicit use cases ('Use it to answer "what are our competitors running that's new?", to feed a teardown, or to save something worth keeping'), and explicitly states what it does NOT do ('never triggers a check (set_competitor_watch({runNow:true}) is what runs one)'). This clearly delineates when to use this tool versus its sibling that performs the actual run.

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