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 discloses the ~10 second latency, the one-ad-per-call constraint, the exact rendering behavior, and the precondition that it only works for ads the search already returned. It does not explicitly say 'read-only', but the verb 'Show' and the framing as public transparency data make this clear enough.

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 slightly longer than minimal but every sentence earns its place: it front-loads the core purpose, then covers video playback, usage timing, performance, sibling distinction, and a precondition. The all-caps emphasis is stylistic noise, but the structure is logical and scannable.

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?

Despite no output schema, the description tells the agent what the result looks like (card with creative, copy, page name; playable video), where the input id comes from, how long the call takes, the single-call constraint, and when to use an alternative. Nothing essential to correct invocation is missing.

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 input schema already covers both parameters at 100% with detailed descriptions, so the baseline is 3. The description reinforces the workflow ('pass the ad's id from the search results') and mentions 'One ad per call', but these are largely redundant with the schema or are usage constraints rather than new parameter semantics.

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 states a specific action ('Show what an Ad Library ad ACTUALLY LOOKS LIKE') and names the concrete deliverables: creative, copy, page name, and a self-contained card with playable video. It also clearly distinguishes itself from siblings, notably adsap_search_ad_library (read text vs. see) and adsap_get_ad_preview (competitor vs. own ads).

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?

Explicit usage guidance is present: 'Use this after adsap_search_ad_library whenever the user wants to SEE a competitor's ad rather than read its text' and 'for those use adsap_get_ad_preview' for own ads. It also states the prerequisite (ad id from search results) and the single-ad-per-call limit, leaving no ambiguity about when to invoke it.

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