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

No annotations exist, so the description carries the burden; it discloses the aggregation granularity (daily) and that the result covers a single metric, which is genuinely useful behavioral context. It omits auth/permission needs, error behavior, and pagination, so it is not complete.

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?

Front-loaded with the core purpose, then prerequisites and optional params in a compact second sentence. The long inline enum is somewhat bulky but maps to the parameter, so little is wasted.

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 deeply nested schema with no output schema and 0% description coverage, the description covers the top-level requirement but leaves most nested fields (timeWindow shape, platform, metadataFilters) unexplained. Adequate but with clear gaps.

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 names the required baseExecutionScope and its required subfields and lists the optional metricType values, but it repeats the schema enum and gives no meaning for the enum members, timeWindow formats, platform, metadataFilters, or automationEmitsOnly.

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 specific verb+resource: 'TrueCoverage daily time series for one metric', which is more precise than the sibling names alone. It does not explicitly contrast with near-neighbors like get-truecoverage-event-transition or get-truecoverage-events, so it falls short of a 5.

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 states the prerequisite ('Requires baseExecutionScope (environment + timeWindow)') and that only one metric is returned, which implies usage. But it gives no when-to-use-vs-alternative guidance against the many TrueCoverage siblings.

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