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 clearly states the operation is read-only, notes it fetches live from Meta, and explains the semantic significance of object_story_id / effective_object_story_id as the underlying post carrying likes and comments. This goes well beyond a bare 'get ad' statement.

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 front-loaded with the core action and scope, followed by return contents, sourcing guidance, use cases, and the mutation alternative. Each sentence earns its place; there is no filler or repetition of schema details.

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 two-parameter read tool with no output schema, the description is complete: it lists what the response contains, how to get the required IDs, when to use the tool, and that it is read-only. Nothing needed for correct selection and 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?

Schema coverage is 100%, so the baseline is 3. The description adds value by telling the agent where to source ad_id (from adsap_list_ads or adsap_get_insights), which is not in the schema. It does not elaborate on ad_account_id beyond the schema, but the schema already describes it clearly.

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 and resource: 'Read ONE ad in full, live from Meta.' It enumerates the exact content returned (creative texts, links, media hashes, Page/Instagram identity, status, timestamps, object_story_id, raw specs), making the tool's scope unmistakable. It also distinguishes itself from the mutation sibling adsap_replace_ad_creative by explicitly positioning this tool as read-only.

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: 'inspect an ad's copy and media, to replicate an ad, or to answer 'what does this ad say / link to?''. It also provides a when-not case by directing creative changes to adsap_replace_ad_creative, and tells the agent where to obtain ad_id from adsap_list_ads or adsap_get_insights.

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