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

Goes well beyond the annotations by describing the preview-by-default safety flow, the name-mismatch blocking behavior that requires acknowledgement, and the plan-dependent caps (3 Analytics/Ads/Meta on paid, 1 on free). It also explains what replace actually does — swapping the main account rather than adding beside it — which is exactly the kind of consequence an agent needs to warn a user about.

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-loads the core identity and the lifecycle position in the first clause, then layers conditions. Some sentences are long and clause-heavy (the paid-plan enumeration), but nearly every clause carries decision-relevant information rather than filler.

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 an 18-parameter mutation with no output schema, the description covers the risky parts: preview gating, mismatch acknowledgement, replacement semantics and plan limits. It does not describe what a preview returns or what happens to the unrelated client-field parameters, but an agent has enough to invoke it correctly and safely.

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 100%, so the baseline is 3; the description adds real meaning on top by tying confirm and replace to the preview lifecycle and by explaining that the more_* array parameters add beside a main account under plan limits. The website, contact_* and crm_location parameters are only covered by the schema, not the description.

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 ('link a connected account') plus the binding scope constraint ('to a client that ALREADY exists'), and positions it in a lifecycle relative to the connect step. An agent can distinguish it from connect_* and unlink_account without opening any 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?

Clearly states when to use it: after connecting a platform, when the client exists but the account is unplaced, and it quotes the refusal message that signals this tool is needed. It also conditions confirm, replace and acknowledge_mismatch on prior preview output. It stops short of naming sibling tools (connect_google, create_client, list_connected_accounts) as explicit alternatives.

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