diagnose_performance

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

The description declares read-only behavior via the '[Ads / read]' prefix and explains that it is a local stub for introspection, not a full implementation. This adds important behavioral context beyond the name. However, without annotations, it could further clarify that no destructive actions are taken, but the read nature is clear.

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 two sentences, highly concise, and front-loads the core purpose. Every word earns its place: '[Ads / read]' for type, 'SP/SB/SD root cause analysis' for domain, 'between date ranges' for scope, and the stub disclaimer for context.

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?

The tool has 7 optional parameters, no output schema, and no annotations. The description explains the tool's purpose and local limitation but does not describe what the output contains (e.g., what root cause analysis results look like). Since the agent cannot infer return structure, the description falls short of full completeness.

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 has 100% parameter description coverage, with clear descriptions for each field (e.g., start_date, end_date, asin, sku). The tool description adds no additional meaning beyond the schema, such as how parameters influence root cause analysis output. Baseline 3 is appropriate given high schema coverage.

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 it's a read tool for ads root cause analysis (SP/SB/SD) by date range. The verb 'diagnose' is implicit in the name but reinforced by the phrase 'root cause analysis'. It distinguishes from sibling tools like get_campaign_performance by focusing on diagnosis rather than raw metrics.

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 notes the tool is only functional on a hosted endpoint and is a stub locally, which is useful guidance. However, it does not explicitly state when to prefer this tool over other performance analysis tools (e.g., get_campaign_performance, get_keyword_performance), leaving ambiguity for the agent.

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