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

Annotations already establish write (readOnlyHint=false), non-destructive, open-world. The description adds genuinely non-obvious behavior: setting default_value forces always_use_default_value and causes supplied tag/upload values to be ignored, plus the dry-run semantics of validate_only. It does not mention permissions or whether duplicates are rejected, which keeps it below 5.

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?

Front-loads the purpose and the downstream-linkage in the first two lines, then one line per parameter — dense and scannable. It is longer than average, but nearly every line contributes enum or constraint information that the schema lacks; only the trailing workspace note is filler-ish.

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?

Seven parameters with zero schema coverage and a real create operation; the description covers six of them with values and side effects, explains the dry-run flag, and a rich output schema exists so return shape needn't be restated. An agent has what it needs to call this correctly.

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 0%, so the description must carry the parameter burden and largely does: it enumerates category values (QUALIFIED_LEAD, LEAD, PURCHASE, SIGNUP, SUBMIT_LEAD_FORM), type values (UPLOAD_CLICKS/WEBPAGE), counting_type values, and explains the default_value/always_use_default_value interaction. Only 'name' is left undocumented, which is partly implied by the example but is the single required parameter.

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+resource ('Legt eine neue Conversion-Aktion an') with a concrete example, and immediately ties the output artifact (resource name/ID) to the follow-up tool ads_upload_conversions. That distinguishes it from ads_update_conversion_action and ads_list_conversion_actions without requiring the schema.

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?

Gives actionable when-to guidance for two parameters: default_value should be omitted when real per-conversion values are booked via ads_upload_conversions, and validate_only=True is the dry-run path. It does not explicitly name ads_update_conversion_action as the alternative for modifying an existing action, so it stops short of full alternative routing.

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