meta_ads_analysis_placements

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

Declares read-only and describes return rows with specific fields (spend, conversions, CPA, ctr, recommendation). No annotations are provided, so the description carries the full burden, and it does so adequately, though it could mention if any side effects exist (none expected).

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?

Two sentences deliver the core purpose and usage context, followed by a one-sentence usage guideline. No wasted words; front-loaded with actionable information.

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?

Given the absence of output schema, the description explains return rows and fields. Schema covers all parameters. Sibling tool references are provided. The description is complete for a placement analysis tool.

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?

Input schema has 100% coverage; all parameters are described in the schema. The description only restates the period options ('Meta predefined ranges ... or explicit'), adding no new meaning. Baseline score of 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?

Description clearly states the tool scores delivery efficiency across Meta placements and flags best/worst. It lists specific placement examples and metrics returned, distinguishing it from sibling meta_ads_insights_breakdown which provides raw numbers.

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?

Explicitly says 'Call this when CPA drifts on a campaign' and directs users to an alternative tool for raw numbers: 'For raw numbers use meta_ads_insights_breakdown with breakdown='placement'.'

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