Read the activity history

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds context that the resource is a 'local mutation ledger' and enumerates filter dimensions, which is useful beyond annotations. However, it does not describe return format or any additional behavioral nuances, though an output schema exists. This adds moderate value beyond the annotations.

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 a single, efficient sentence that front-loads the primary action ('Read the local mutation ledger') and then lists the filter dimensions. There is no wasted wording, and every part contributes to understanding the tool's scope.

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?

Given the tool has 7 parameters, an output schema, and annotations fully covering safety, the description is largely complete. It explains the core function and the available filters. It does not explicitly mention output details, but the output schema presumably covers that. The only minor gap is that it doesn't state why one might use this tool (e.g., for debugging), but given its uniqueness among siblings, this is acceptable.

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% with each parameter having a description, so the schema fully documents parameters. The description summarizes them as 'time, tool, event, plan, and operation filters', which maps to since/until, tool, event, plan_id, operation_id. This adds minimal meaning beyond the schema's own descriptions, so the baseline of 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?

The description clearly states the tool reads a 'local mutation ledger' and lists the specific filters (time, tool, event, plan, operation). This is a specific verb+resource combination that distinguishes it from all sibling tools, which are email-centric. The title 'Read the activity history' reinforces it, but the description goes further.

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 implies usage for inspecting mutation history, but does not explicitly state when to use it versus alternatives or provide exclusions. Since no sibling tool is similar, the need for explicit guidance is lower, but the description still lacks an explicit 'use this when...' statement. Thus, usage is implied but not elaborated.

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