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

With no annotations, the description carries the full behavioral burden, and it does disclose two useful traits: the fixed cost (1 credit per call) and the expected output shape (English translation plus next run times), which matters since there is no output schema. It is silent on error behavior for malformed or 6-field expressions and on any validation rules, so the disclosure is only partial.

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, zero filler. The purpose is front-loaded and the cost caveat follows it, which is the right order for an agent deciding whether to call.

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 two-parameter tool with no annotations and no output schema, the description should cover return format, the second parameter, and failure behavior. It covers the return format and cost, but leaves `runs` unexplained and says nothing about how invalid expressions are handled, so it is adequate rather than complete.

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 coverage is 50%: the `expression` parameter has an example but the `runs` parameter has no description at all, only schema constraints (default 5, max 20). The description contributes the meaningful constraint that the input is a 5-field expression, but it never explains what `runs` controls beyond the vague phrase 'list the next run times'.

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 specific verbs (translate, list) against a specific resource (a 5-field cron expression), and names the concrete output (plain English plus next run times). No sibling tool in the list overlaps with cron parsing, so there is nothing to disambiguate against; an agent can select this with confidence from the title and first sentence alone.

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 implied by the purpose statement (call it when you need a cron expression explained), and the cost note gives a reason to weigh the call. However, there is no explicit when-to-use/when-not guidance, no mention of how it relates to any alternative, and no prerequisites such as expression validation expectations.

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