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

Annotations already declare read-only, open-world, non-destructive behavior, so the safety profile is covered. The description adds the custom integrated-report intent and examples, but says nothing about account access, rate limits, pagination, or result behavior; with annotations, a 3 is appropriate.

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?

It is one front-loaded sentence with no filler; the examples are useful rather than padding, though the long parenthetical list is dense. Appropriate for a query tool.

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 an 11-parameter custom reporting tool with no output schema, the description covers the core selection model but omits return shape, required parameter combinations, and practical account/date constraints. It is adequate but not fully complete.

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 description adds useful example values for dimensions and metrics (e.g., stat_time_day, cost_per_conversion) that are not in the schema. However, 4 of 11 parameters lack schema descriptions, and the description does not explain level enums, report_type, date handling, or limit/account/folder semantics, so the baseline 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?

States a specific verb ('Run a custom read-only integrated report') and resource (TikTok), and scopes it to 'analysis not covered by other tools' with example dimensions and metrics. This is clear enough to distinguish it from standard reporting tools, though it does not name the specific sibling to use instead.

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 phrase 'analysis not covered by other tools' gives a when-to-use signal, but it does not explicitly identify which siblings cover standard reporting or breakdowns, nor does it state prerequisites or exclusions. The agent must infer the boundary.

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