List one venue's balances

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

Goes well beyond the annotations: it discloses the required `portfolio:read` scope, a concrete rate limit (60 rpm) that is shared across the entire `venue-private` group, and the non-obvious fact that each call also consumes the caller's own allowance at the venue. The annotations only declare it as a safe idempotent read; this adds the operational cost profile an agent needs.

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 core purpose, then scope, rate limit and routing. Every sentence carries information, though the closing clause ('instead of being asked whether one has') is slightly convoluted and could be tightened.

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 single-parameter read tool with an output schema absent but a very simple return shape, the description covers auth, rate limits, and alternatives. It does not describe the returned balance structure, which is a minor gap given there is no output schema.

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 100% and the single `venue` parameter already has an enum plus a clarifying note about the market half of the name, so the schema does the heavy lifting. The description adds only the scoping rationale ('Name a venue when you only need one'), not new format or syntax detail. Baseline 3 applies.

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 states a precise verb+resource+scope: balances, restricted to a single named venue. The scope qualifier ('one venue', 'Name a venue when you only need one') implicitly separates it from the sibling list_balances, which an agent can infer covers all venues.

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?

Explicit when-to-use ('Name a venue when you only need one') and an explicit when-not-use with a named alternative ('For anything you would otherwise poll for, follow the order stream'). It also warns against polling, which is actionable routing guidance rather than generic advice.

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