meta_ads_analysis_cost

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

No annotations provided, so the description carries the full burden. It declares 'Read-only', which is good, and describes the output format (decomposition with per-driver magnitude and action hint). It doesn't detail error handling or behavior on invalid inputs, but is generally transparent.

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 a single, well-structured paragraph that covers purpose, output, usage context, and read-only nature. No redundant sentences.

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 no output schema, the description adequately explains the return value (decomposition with drivers, magnitude, action hint). It also clarifies it's read-only and provides usage context. Compared to sibling tools, it clearly fills a niche for cost diagnosis.

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%. The description adds value beyond the schema by explaining the fallback behavior for account_id, the detailed period format including cost implications, and the expected format for campaign_id (not elaborated but the schema description handles it).

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 clearly states the tool diagnoses rising spend or degrading CPA on a Meta Ads campaign, returning a decomposition attributing cost changes to specific drivers with magnitude and action hints. It distinguishes from sibling tools by focusing on root-cause analysis of cost changes.

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 advises using when the operator reports 'why did CPA jump', and clarifies it separates auction-side from creative-side causes. While it doesn't explicitly state when not to use it, the use case is well-defined. Could be improved by mentioning when to use alternative analysis tools.

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