What Changed

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 that the tool returns a 'structured diff' of all graph changes, but it does not elaborate on whether this includes additions, deletions, or metadata, or on potential performance implications. The description does not contradict 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, well-structured sentence that immediately states the core action and scope. No fluff or redundancy; every word contributes to understanding the tool's purpose.

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 good annotations and full schema coverage, the description is adequate but not rich. It does not describe the exact return format (beyond 'structured diff') or clarify how 'since' and 'since_session' interact when both are provided. The absence of an output schema makes this a noticeable gap, though the tool's simplicity keeps it 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 description coverage is 100%, with each parameter already having meaningful descriptions. The tool description adds no additional parameter-level detail beyond echoing 'since a timestamp or session start', which is already captured in the schema. Baseline 3 is appropriate because the schema does the heavy lifting.

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 uses a specific verb ('Retrieve') and clearly identifies the resource ('structured diff of all graph changes') with a temporal scope ('since a timestamp or session start'). It distinguishes itself from sibling tools like get_node_history (node-specific) and diff_snapshots (snapshot comparison).

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 the tool is used to obtain changes since a point in time, but it does not explicitly state when to use it over alternatives like get_event_log or diff_snapshots, nor does it mention exclusions or prerequisites. Clear context but no differentiation from similar sibling tools.

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