direct_check_changes

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the description's 'Read-only' is largely redundant. It does add the timestamp format expectation (UTC ISO, Z) and the incremental-sync framing, which is modest but real value beyond the annotations.

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-loaded with the core question ('what changed') followed by method enumeration and the one usage rule. Compact with little waste, though the parenthetical method glosses are dense.

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?

An output schema exists so return values need no explanation, but for a 6-parameter, 0%-documented tool the description is only partially complete: the id/field parameters remain undocumented, leaving the agent to infer which combinations are valid.

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% across 6 parameters, so the description carries the full burden. It explains the method enum values (checkCampaigns/check/checkDictionaries) and the timestamp format, but leaves ad_ids, campaign_ids, ad_group_ids and field_names entirely unexplained, including which ids pair with which method.

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 resource ('what changed in Direct since timestamp') and enumerates the three Changes methods, so the agent knows this is a changes/delta query, not a full listing. It does not name a sibling tool to differentiate against, but the verb+resource is unambiguous.

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 one clear usage rule ('use for incremental sync instead of re-reading everything') but no explicit tool alternatives and no guidance on which method or id parameter to pick for a given task. Usage is implied rather than fully specified.

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