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

Annotations already declare readOnlyHint, openWorldHint and destructiveHint=false, so safety is covered. The description adds genuinely new behavioral context — 'free, 0 credits' — which is a real operational property not present in the annotations. It stops short of describing latency or staleness semantics, so not a 5.

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 core intent and cost are front-loaded in the first clause, and the second sentence carries the decisive call guidance. The middle clause is a long comma-separated inventory that is dense but each item is informative, so only minor trimming is possible.

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 zero parameters, full annotation coverage and an output schema present, the description does not need to document return structure or arguments. It supplies the one thing structured fields cannot: when an agent should interpose a freshness check before spending calls elsewhere.

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, so there is nothing for the description to disambiguate. The baseline for parameterless tools applies, and the description's enumeration of returned fields is a bonus rather than a requirement.

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 precise scope ('When the data last changed') and enumerates exactly what is returned: newest published date per snapshot frequency and asset class, preliminary/final flag, row counts, release timestamps, market-level date, recent releases and the schedule. It clearly separates this freshness tool from content-returning siblings such as get_summary, get_search, get_universe and the ticker tools.

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 an explicit call condition ('before re-pulling summaries, search results or a universe') and names the anti-pattern it replaces ('instead of polling ticker tools'). The agent has both the trigger and the alternative spelled out, plus the cost incentive.

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