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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description still adds real value beyond them: it clarifies that the tool reads recorded state rather than rerunning checks, and it warns that gap states are not positive results — an interpretive nuance annotations cannot express.

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 short sentences, front-loaded with the returned data, then the behavioral boundary, then the interpretation caveat. No filler, no repetition of the title or annotations, and each sentence changes what the agent knows.

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 carries the burden of describing the return payload, and it does so field-by-field while also flagging that absence of a check is not a passing check. For a one-parameter read tool this is complete enough to invoke and interpret correctly.

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 is a single parameter and schema description coverage is 100%; the schema already explains that slug is the 'Builder slug from search_builders.' The description adds no further meaning about the slug (source of the value, format, lookup behavior), so the baseline 3 applies when the schema does all the work.

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 uses a specific verb ('Read') and enumerates the exact resource contents (per-source check states, result details, attempt/success dates, next due dates, source URLs), so an agent knows precisely what comes back. It does not explicitly name or contrast itself with siblings like get_builder_risk or get_builder_timeline, so sibling differentiation is only implicit via the 'coverage/check state' scope.

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 gives a clear negative boundary: 'This reads recorded state; it does not rerun checks or enable monitoring,' which tells the agent not to expect any triggering behavior. It also tells the agent how to read ambiguous results ('Unchecked, stale and unavailable are gaps, not clear results'). It stops short of naming an alternative tool or stating a positive 'use this when' condition, so it does not reach a 5.

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