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

With no annotations, the description carries the full burden, and it does disclose the return contract in detail (key, label, type, required, help text, options), which is the main behavior an agent needs since no output schema exists. It is silent on ordering, caching, or how the options list behaves when empty, so it is strong but not exhaustive.

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 return contents are front-loaded and the actionable usage tip is placed last where it is most useful, and every clause 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?

For a parameterless lookup with no annotations and no output schema, the description substitutes for the missing output schema by enumerating the returned fields, which is exactly what is needed. The only residual gap is the absence of any hint about field ordering or whether the set is static versus dataset-dependent.

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?

There are zero parameters, which sets the baseline at 4. The description introduces no parameter-level semantics because none are needed, and it does not confuse the reader with phantom inputs.

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 precisely what the tool returns: 'Every field of the Tide Times Compare enquiry: key, label, type, whether required, help text and the allowed options where there are any.' This is a specific resource with an enumerated return shape, letting an agent distinguish it from sibling tools like dataset_columns. It does not, however, explicitly contrast itself with the nearby enquiry_describe or submit_enquiry.

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?

The second sentence gives a concrete downstream workflow hint: 'Pass answers to submit_enquiry keyed by field key,' which links this lookup to its consumer. But it never says when to call this versus enquiry_describe, nor states any precondition for invoking it, so the usage guidance is implied rather than explicit.

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