triggers_update

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

With no annotations, the description carries the full burden. It discloses that the tool is a write operation (via [WRITE]) and that it requires an environment variable and a confirm parameter. However, it does not describe other behavioral traits such as what happens if the trigger doesn't exist, whether updates are incremental or full replacement, or what the response format is.

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 very concise: one sentence stating the action and a second sentence listing requirements. It is front-loaded and to the point. However, it could be slightly more structured to include parameter guidance without becoming verbose.

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 the tool's complexity (12 parameters, nested objects, no output schema, no annotations), the description is too minimal. It does not explain what the tool returns, how the filter object should be constructed, or any side effects. The description is inadequate for an agent to confidently invoke the tool correctly in various scenarios.

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%. The description does not explain any parameter beyond requiring 'confirm=true.' It does not clarify the roles of accountId, containerId, workspaceId, triggerId, or the nested 'filter' and 'eventName' objects. This leaves the agent to rely solely on parameter names, which may be insufficient for correct invocation.

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 'Update a GTM trigger' with a specific verb and resource. The [WRITE] prefix adds clarity. It distinguishes from sibling tools like triggers_create and triggers_delete by the update action, though it doesn't explicitly differentiate from other update tools (e.g., tags_update) beyond the resource name.

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 mentions prerequisites: 'Requires GTM_MCP_ENABLE_WRITES=true and confirm=true.' This provides useful usage conditions but does not explicitly state when to use this tool versus alternatives (e.g., triggers_create vs triggers_update). Usage is implied by the update nature.

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