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

Annotations already cover readOnly/idempotent/non-destructive/closed-world; the description adds real context beyond them: ordering (newest first), the fields returned (calls left, end time, totals, current price), the definition of a day pass, and the required Last Price credential with price:compute scope. That auth requirement is meaningful operational disclosure.

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 action and result shape ('Read your workspace's day passes, newest first'). It is dense with multiple clauses but each adds signal; the credential note at the end is slightly tacked on but still earns its place.

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?

No output schema exists, so the description carries the return-value burden, and it does—listing calls left, end time, total remaining, and current new-pass price. Combined with the auth scope note and sibling reference, nothing an agent needs to call it correctly 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?

Zero parameters, so the schema baseline of 4 applies. The description adds no parameter detail because there is nothing to parameterize, which 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?

States a specific verb+resource ('Read your workspace's day passes') and adds distinguishing scope ('newest first'), plus names buy_day_pass as the mutation sibling. An agent can distinguish it from buy_day_pass without opening the schema.

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?

Explicitly routes to buy_day_pass for purchasing a pass and states the credential/scope prerequisite. It doesn't spell out conditions for skipping the call, but the read-vs-buy split with the sibling is clear.

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