gaps

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

With no annotations, the description carries the full burden. It does disclose the key behavioral trait that domain='fit' is non-functional, and defines gap semantics (never synced vs synced-but-empty/failed), which is genuinely useful. However, it says nothing about return shape, permissions, or reliability limits, leaving real gaps for a read-style tool with zero annotation coverage.

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?

Three sentences, front-loaded with the core purpose, followed by domain caveats and the gap definition. Minimal waste; the parenthetical is slightly awkward but earns its place by preventing a doomed 'fit' 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?

Covers purpose, domain semantics, and gap definition, but with no output schema and 0% parameter coverage, the description omits date format and any hint of what the returned list looks like. Adequate but with clear omissions for a 3-required-param tool.

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 description coverage is 0%, so the description must compensate. It does document the domain enum values and the fit degradation, which is real added value the schema lacks. But the two date parameters (date_from/date_to) get no format or syntax guidance despite being bare 'string' types, leaving 2 of 3 params under-specified.

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 precise verb+resource: 'List days with no usable data over a date range,' and goes on to define what a gap is. This clearly differentiates the tool's function from sibling query tools, though it never names an alternative sibling the way a 5 would.

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 (find uncovered days), and the note that domain 'fit' always degrades to 'domain not yet available' is a useful when-not caveat. But there is no explicit statement of when to choose this over anomalies, baselines, or query_health, nor any stated prerequisites.

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