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

Annotations already declare readOnlyHint, idempotentHint and closed-world, so the safety profile is fully covered by structured data. The description adds only the domain note that the coverage is 'normalized' Seiche money-market data; it says nothing about result size, ordering, or whether the list is static or reflects live availability.

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?

A single five-word phrase, front-loaded with the verb. Nothing is wasted, but the extreme terseness edges into under-specification rather than economical precision.

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 no output schema, the description must convey what a caller gets back, and 'coverage' does not. For a zero-param enumeration tool whose entire value is the returned list, failing to describe the shape or granularity of that list leaves a real gap.

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 with 100% schema coverage, so there is nothing for the description to disambiguate. Baseline 4 applies — no semantic gaps are possible with an empty input schema.

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 verb 'List' and the domain qualifier 'Seiche money-market' are specific, but the object 'coverage' is undefined — an agent cannot tell whether this returns markets, tickers, date ranges, or dataset availability. It is distinguishable from seiche_observations only by the ambiguous word 'coverage', not by an explicit statement of difference.

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?

There is no indication of when to call this rather than seiche_observations, list_datasets, or corpus_catalog — all plausible siblings for discovering what data exists. No prerequisites, no exclusions, no routing guidance of any kind.

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