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

Goes well beyond the annotations by disclosing patch semantics, an optimistic-concurrency guard (a trigger edited by someone else in between is refused rather than overwritten), and the exact blast radius: workspace settings including a live trigger are overwritten, but the live site only changes when a human publishes. The destructiveHint=true annotation is corroborated and given concrete meaning rather than merely restated.

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 verb and scope, then safety-relevant behavior, with no filler sentences. The trailing 'Tools revision: d80f65c0.' is metadata noise that does not help an agent decide or call the 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?

An output schema exists, so return values need not be described, and the description covers the mutation, the concurrency guard, and the publish boundary. The gap is parameter-level guidance for the seven undocumented fields on a 9-parameter mutation tool.

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 9 parameters, and the description only explains the replacement semantics of `parameter` entries and filter lists. It adds real meaning for those two fields but leaves name, type, event_name, container, trigger_id, auto_event_filter, and custom_event_filter undocumented in both schema and prose, so it only partly compensates for the coverage gap.

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 and resource (update a trigger), the addressing key (by trigger id), and the workspace scope (the managed AdCopilot workspace), plus a staging qualifier that separates it from anything that would go live. An agent can distinguish it from gtm_create_trigger and gtm_update_tag without opening either 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?

Guidance is clear: use it with a trigger id in the managed workspace, and only the passed fields change, so it is the right call for partial edits rather than full replacement. It does not explicitly name sibling alternatives or state when to prefer create/update-of-tag instead, so it stops short of a full routing statement.

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