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

With no annotations provided, the description carries full responsibility for behavioral transparency. It clearly marks the operation as read-only, explains the 402 use case, details the 'blocked' field's consequence (every metered call returns 403), and specifies raw integer units for deposit_balance and total_spent. This goes well beyond a generic 'gets workspace info' statement.

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 front-loaded with the core purpose, then expands to return values and error behavior, and ends with a practical usage recommendation. Every sentence adds non-redundant information; there is no 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?

Even without an output schema, the description fully explains returned fields (deposit_balance, total_spent, is_trial, blocked), unit semantics, and the 403/402 implications. It also clarifies key requirements and provides a concrete pre-flight use case, so an agent has everything needed to decide when and how to call 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?

The schema already fully documents both parameters (api_key and workspace_id) with detailed descriptions. The description adds some context by clarifying that api_key can be a sub-key, not necessarily the owner_key, and by tying usage to a 402 check. But most parameter meaning comes from the schema, so the baseline 3 is appropriate.

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 opens with a specific verb and resource — 'Check a workspace's current balance and status' — and immediately distinguishes the tool as 'the read-only counterpart to every other workspace tool.' This makes the tool's role clear and separates it from sibling tools without needing to inspect their schemas.

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?

It gives concrete usage guidance: 'Call this before a batch of expensive operations to confirm you won't hit a 402 partway through.' It also explains the tool accepts owner_key or sub-key. It does not explicitly name a specific alternative tool, but the read-only-counterpart framing implies when this tool is appropriate versus other workspace operations.

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