Choose which accounts a brand may use

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

Annotations already include idempotentHint=true and destructiveHint=false, but the description goes beyond: it clarifies that the operation REPLACES the current selection, that leaving out an account un-shares it, that an empty list refuses publishing (fails closed), and that the server re-verifies every id against the live connection. This adds critical behavioral context not present in annotations, such as the fail-closed design and validation logic.

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 dense and informative but somewhat long, including a redundant list of providers that duplicates the schema enum and a trailing 'Free.' that appears out of place. The core action is front-loaded, and the behavioral warnings follow logically. It could be trimmed slightly without losing value, but it remains well-structured for an agent to parse.

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—multiple providers, side effects on publishing permissions, and failure modes—the description covers essential aspects: replacement semantics, empty-list behavior, fail-closed design, id verification, and a user-interaction cue. There is no output schema, so return-value explanation is not required. The description leaves little for an agent to guess.

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?

The input schema covers both parameters (provider and accountIds) with descriptions, achieving 100% schema coverage. The description adds marginal value: it reiterates that ids come from list_connector_accounts and that an empty array shares nothing—both already in the schema. The provider enumerations are listed in the description but duplicate the enum in the schema. No new semantic layer is provided beyond what the schema already states.

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 states a precise action: 'Set WHICH of a connector's accounts this brand is allowed to post to and spend from', followed by a concrete list of account types (Facebook Pages, Google Ads customers, LinkedIn Pages, etc.). It clearly distinguishes itself from sibling tools like list_connector_accounts (listing vs. setting), disconnect_connector, and leave_connector by focusing on permission assignment. The verb+resource is specific and 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?

The description gives explicit usage guidance: 'Pass ids from list_connector_accounts' and 'Ask the user which accounts they mean; posting as the wrong Page is a public mistake.' It communicates the replacement behavior and the empty-list consequence, but does not explicitly state when _not_ to use this tool versus alternatives like leave_connector. However, the context is strong enough that an agent would infer when to use it.

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