emet_gaps

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

Annotations already declare readOnly/idempotent/non-destructive, but the description adds value beyond them: "identifies and never fills," the return expectation "digest mismatches (the alarm - expect zero)," and the note that counts are complete while ids are capped. It stops short of describing the response shape in full.

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?

Dense but front-loaded: the operation and its read-only nature come first, then the enumerated classes, then usage. The list of gap classes is long but each item is distinct and informative. The opening metaphor is a minor flourish that costs a few words.

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 read-only diagnostic query with no output schema, the description is largely sufficient: it names every gap class, states counts are complete, and explains what closing a gap entails. Only the exact response structure and id-format remain unspecified, which is a minor 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?

Schema description coverage is 100%, so the schema already documents layer, limit, and since in detail. The description adds no parameter-level syntax or defaults; its references to tags, sessions, and the 2026-09-05 boundary describe gap classes rather than inputs. Baseline 3 applies.

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?

After a metaphorical opening ("the record's honesty about its own holes"), it states a concrete verb and resource: "Counts, with the ids behind them, for each gap class," and enumerates those classes (unsourced assertions, digest mismatches, broken supersession, etc.). This distinguishes it from siblings like emet_status or query_layer, though the poetic framing costs some immediate clarity.

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?

Explicit triggers are given: "Call it when asked how trustworthy the record is, before a consolidation pass, or after any migration." It also names the follow-up path, routing remediation to revise_memory "with a real derived_from where the source is knowable," and clarifies the tool itself never fills gaps.

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