memory_history

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

Annotations already declare readOnlyHint=true, but the description adds substantial context: how revisions are created (update() snapshots the displaced body before overwriting), and critically that the return shape is mode-dependent — metadata only for listing vs full content for a single read. This is behavioral detail the annotations cannot convey.

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?

Four tight sentences, front-loaded with the core purpose and then the mechanism, modes, and routing. No filler; each clause carries information (how data arrives, two modes, the alternative tool).

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?

With no output schema, the description carries the return-value burden and does so: listing returns metadata (id, op, replaced_at, char count) and single-read returns full content. Combined with the mode rules and the restore pointer, an agent has everything needed to call 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 100%, so both parameters are already documented (baseline 3). The description adds real semantic value by mapping parameter combinations to behavior: 'ref alone' vs 'ref + revision_id' determine listing vs single-snapshot read, and it clarifies what the listing returns. It stops just short of adding syntax/format detail beyond the schema.

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+resource ('Body-revision history for a memory') and immediately clarifies it is the read surface of a write/read pair with update(). It distinguishes itself from memory_revision_restore by name, so an agent can tell the read from the restore tool without opening either schema.

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?

Explicitly describes the two invocation modes (ref alone lists, ref+revision_id reads one) and names the correct alternative for restoring ('use memory_revision_restore'). This covers both when to use this tool and when to route elsewhere.

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