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

Annotations already flag destructiveHint=true, idempotentHint=true and openWorldHint=true, and the description adds meaningful context beyond them: the Agency-plan token requirement, that one token can serve many businesses, that link_project mutates the Nimbata project by adding KaiCalls tags, and precisely what the writeback contains (source, UTM, click ids, outcome tag, qualified tag, summary comment). What it never discloses is the consequence of the destructive branches – what disconnect removes, whether prior tags or history are stripped on unlink_project, and whether disconnecting is reversible.

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 integration purpose, then a compact action-by-action clause list using brace notation to bind parameters to actions. Given five sub-actions and several constraints, the density is justified and no sentence is 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 a five-action mutation tool with 7 parameters and 0% schema description coverage, the definition covers purpose, prerequisites, cross-system side effects and an external setup step. The remaining shortfall is the destructive semantics of unlink_project and disconnect plus the meaning of the required business_id, which an agent must guess. An output schema exists, so return values need not be explained.

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%, so the description carries the full burden, and it does substantial work by mapping api_token, project_id, target_business_id (marked optional), link_id and enabled to the actions that consume them. Gaps remain on the required business_id, which is only implied by 'a business's line' and the admin-role sentence, and on the fact that only business_id and action are required at the top level.

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 names a specific resource (Nimbata call tracking) and enumerates five concrete actions with their effects: connect saves a token, link_project attaches calls and tags, set_writeback toggles writeback, and so on. An agent can tell what the tool does without opening the schema. It stops short of a 5 because it never distinguishes itself from the read-oriented sibling get_nimbata, so the boundary with the read tool is left implicit.

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?

Each action's purpose implies when to use it, and the description adds two real prerequisites: a current admin role on every business involved, and that routing stays in Nimbata so the KaiCalls number must be added to the call flow there. However, there is no explicit when-not guidance, no statement of the ordered workflow (connect before link_project), and no pointer to get_nimbata for read access.

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