history_sources

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering safety. The description adds that it lists coverage, revision, and timestamps, and clarifies it is not live discovery, which provides additional behavioral context beyond the annotations. This is useful and consistent.

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, compact sentence that front-loads the core action and resource. Every word earns its place, and the clarifying 'not live discovery' adds meaningful distinction without waste.

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 zero-parameter tool with a clear output schema (not shown but noted), the description is complete. It states what the tool does, what it covers, and explicitly rules out live discovery. The distinction from siblings is clear, and an agent can correctly invoke it without additional information.

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 are zero parameters, so schema description coverage is trivially 100%. With no parameters, the description carries no burden to explain them, and the baseline of 4 applies. No additional param info is needed.

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 states a specific verb ('List') and resource ('imported source coverage, revision and timestamps'), and explicitly adds 'not live discovery' to distinguish it from live discovery tools. This differentiates it from siblings like history_list, history_search, and history_read, which are about different operations.

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 phrase 'not live discovery' clarifies that this tool is for imported/historical data, not real-time discovery. While it doesn't explicitly name alternatives, the context of the siblings (list, search, read) implies when this tool is appropriate. It gives clear context but no explicit exclusions beyond the live discovery caveat.

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