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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds valuable behavior: the summary mode's token cap, the decisions mode preserving rework reasons after overwrite, and the full mode capped at 100 events with an explicit note. This goes beyond annotations and informs the agent about expected output and limitations.

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?

The description is dense but efficient. It front-loads the purpose and use cases, then packs the three modes with concrete details in a single, well-structured sentence. Every clause earns its place without fluff.

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 tool with two parameters and no output schema, the description fully covers what the agent needs: what each mode returns, the cap, and the intended usage scenarios. No critical information is missing for correct invocation.

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 coverage is 100%, but the description enriches the 'mode' parameter by explaining exactly what each enum value returns (summary: card+receipt+counts, decisions: all decisions with verdicts, full: raw journal). This is significant semantic value beyond the schema's simple enum listing.

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 clearly states the tool retrieves the history of a task, not its current fields, and contrasts with current-state tools. It specifies three modes with distinct outputs, making its purpose unambiguous and distinguishable from siblings like list_tasks or get_context.

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 explicit use cases ('before retrying failed work, judging a receipt, or answering why is this still open?') and explains which mode to pick. It does not explicitly name alternatives or state when NOT to use it, but the contexts are clear enough to guide an agent.

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