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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so safety is covered and the description's job is narrower. It adds real value by disclosing the returned content and the feature-gating semantics (which capabilities are Pro), though it says nothing about auth requirements, workspace scoping behaviour for non-active workspaces, or error cases on a free plan.

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 sentences, front-loaded with the return payload and followed by the Pro-feature note that explains why the plan data matters. No filler, no restatement of the title.

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 input parameters, no output schema and full annotation coverage, the description carries the remaining burden by enumerating the returned fields and the plan gating rule. Nothing an agent needs in order to call it correctly or interpret the result 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?

The tool takes zero parameters and the schema is empty, so there is nothing to disambiguate; baseline 4 applies. The description correctly implies the workspace is implicit ('the active workspace's'), which is the one semantic point worth flagging for a parameterless tool.

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?

Specific verb plus resource ('Return the active workspace's plan and usage') followed by an enumeration of exactly what comes back: plan tier, subscription status, seat/project limits vs counts, and trial/period end dates. That enumeration makes it unmistakable against neighbours like get_ai_credits or whoami, which return different slices of account data.

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?

Usage is only implied: an agent can infer it should call this to check whether Pro-gated features (time tracking, costs, RAID, share links, webhooks) are available. There is no explicit 'use this when...' or 'do not use this for...' clause, and no named alternative such as get_ai_credits for credit-specific questions.

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