history_session_validate

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

Annotations already declare readOnlyHint=false and idempotentHint=true, so the safety profile is partly covered. The description usefully adds that the only mutating path is repair, which rebuilds state/manifest from Markdown archives, but it doesn't state that a non-repair run is read-only or what repair does to existing derived files.

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 tight sentences with no filler, and the core action (validation scope) is front-loaded before the optional repair behavior.

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 4-parameter tool with no output schema, the description covers purpose and the repair side effect but leaves the three directory parameters and the notion of 'derived state/manifest' unexplained. It is adequate to select the tool but thin on how to invoke it correctly.

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 only 25%: repair is documented in the schema, while history_dir, project_root, and workspace_root have no descriptions anywhere. The description mentions 'Markdown archives' but does not clarify what these three path parameters are or how they relate, so it fails to compensate for the coverage gap.

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?

States a specific verb ('Validate') and a concrete scope: session numbering, duplicates, and derived state/manifest. This clearly distinguishes it from the sibling read/search/checkpoint tools, though it doesn't name any sibling explicitly.

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?

No guidance on when to run validation versus history_session_read, history_session_search, or history_session_checkpoint, and no conditions given for when repair should be enabled. The agent must infer the trigger conditions entirely.

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