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

Annotations already establish this as a safe read (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower. The description adds genuine behavioral value by disclosing the plan_required failure mode and what it carries, but says nothing about the shape of a successful response or whether the plan is resolved per-account or per-project.

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?

Two compact sentences with the core purpose front-loaded and the error behavior placed second where it belongs. Nothing is padded, though the feature examples ('such as schedules, CRM sync and single sign-on') sit slightly awkwardly between the verb and the member-count clause.

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?

With no output schema, the description does a fair job of naming what comes back (plan, included features, member count) and the error case. The unresolved project_id parameter is the main completeness gap for an agent deciding how to invoke it.

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% for the single project_id parameter, so the description must carry the weight and does not — it never mentions project_id or what supplying it changes. Worse, it frames the result as the 'account's plan' while the only parameter is project-scoped, which leaves the agent unsure whether the parameter is required for meaningful output.

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 uses a specific verb and resource ('Reads the account's plan, what it includes') and enumerates the concrete entitlements covered (schedules, CRM sync, SSO, member count). It does not distinguish itself from near-siblings such as get_account or get_capacity_catalog, but the operation itself is 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?

There is no explicit when-to-use guidance and no named alternative, despite several sibling tools that also report account/plan state (get_account, get_capacity_balance, get_capacity_catalog). The only routing hint is the implicit 'check entitlements' framing, which the agent must infer.

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