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

Goes beyond the annotations (readOnlyHint=false, idempotentHint=true, destructiveHint=false) by disclosing the actual state change—channel synchronization halts until resumed—and by spelling out the return payload {integrationId, action, status, kind}. It also reveals the project_id inference fallback and the project_id_required error path, which annotations cannot express.

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 action and effect, then the usage trigger, then return shape and parameter sourcing—a sensible order. The dense parenthetical about project_id_required and the inline return-object notation make it slightly heavier to parse than necessary.

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 a two-parameter state-toggle tool with no output schema, the description supplies the effect, reversibility, return shape, and both parameters' resolution paths. Nothing an agent needs to invoke it correctly is missing.

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 coverage is 0%, yet the description compensates fully: marketplace_id is sourced from list_marketplaces, and project_id is documented as optional, auto-inferred for single-project customers, and required otherwise with an explicit recovery step (call list_projects). That covers both parameters' provenance and failure semantics.

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 plus the exact effect ('synchronization to the channel stops until it is resumed'), which separates it from resume_marketplace. It never names pause_marketplace_items or pause_ad_items, so an agent must infer from the scope wording that this stops channel sync rather than pausing individual listings.

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 an explicit trigger ('Use this when the user wants a marketplace to stop syncing') and points to resume_marketplace for the inverse. It also routes the agent to list_marketplaces and list_projects for ID resolution, but includes no when-not guidance against the item-level pause siblings.

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