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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals several critical traits: the batch never fails as a whole (per-item failures are inline), publisher records are fetched once per unique domain, and it includes cost and latency details. This goes far beyond minimal requirements and gives an agent a realistic expectation of behavior.

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 well-organized with clear sections (Use this tool when, Inputs, Returns, Cost, Latency) and uses bullet lists for scannability. Every sentence earns its place, providing directly actionable information without fluff. The structure front-loads the core purpose and use case, then details operational behavior.

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 return values, which it does thoroughly (count, verified_count, results with ok/error details). It also covers cost, latency, and edge-case behavior. For a batch tool with this complexity, the description is comprehensive and leaves minimal gaps.

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 schema already covers both parameters at 100%, so the baseline is 3. The description adds meaningful value by showing the exact shape of `items` (including the optional `seller_type?`), explaining that `resolve_chain` applies globally and cross-checks against sellers.json, and detailing the return object. This enriches the schema without being redundant.

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+resource+scope: 'Runs up to 100 ads.txt verifications in a single call.' It explicitly names the batch behavior and distinguishes itself from the sibling `sigil_verify_ads_txt` by framing this as the multi-item counterpart. This makes the tool's purpose unambiguous and distinct.

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 'Use this tool when' section provides explicit conditions: evaluating many supply paths at once (campaign setup, SPO sweep) and wanting one round-trip instead of N calls to `sigil_verify_ads_txt`. This clearly tells an agent when to choose this tool over the singular variant, fulfilling the when/alternatives guidance.

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