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

The annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds meaningful behavioral context on top: 'durable, append-only', 'newest-first', 'one record per committed reactive cycle', and the embedded vs remote/paired storage-mode distinction. This goes well beyond what annotations alone communicate.

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?

Two information-dense sentences with the core purpose front-loaded before the filter and mode details. The parenthetical lists (mutations, derivedUpdated, traces, etc.) add jargon but are relevant to understanding the record contents and earn their place, so the description is efficient without being minimal.

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 query tool with no output schema, the description supplies the important contextual pieces: what a record contains, ordering, durability, filters, and storage-mode differences. An agent has enough to call the tool correctly and interpret the returned records.

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 documents all five parameters. The description groups the filters and clarifies that pathPrefix is a 'canonical address', but it does not add substantial parameter-level semantics beyond what the schema already provides; per the calibration baseline, a 3 is appropriate.

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 opens with a specific verb and resource ('Query a model's durable, append-only audit trail') and states the ordering and record granularity. It explicitly differentiates itself from siblings by calling itself 'the queryable superset of get_history/explain' and explains how it survives the ring-buffer rollover, so an agent can distinguish it without opening schemas.

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?

The description gives clear context for when this tool is appropriate: it is the durable superset that outlives the in-memory ring buffer. It names the alternatives (get_history/explain) and the distinguishing condition, but it does not explicitly state when to prefer those alternatives instead, stopping short of full when/when-not coverage.

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