memory_snapshot_diff

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

No annotations provided, so description bears full burden. It clearly states the tool returns a diff or an error object, implying read-only behavior. It does not mention authentication or side effects, but for a read-only tool the description is sufficient.

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?

Description is concise: one-line summary followed by a short paragraph with additional context. Every sentence adds value. Front-loaded with the primary 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?

Given no output schema, the description adequately explains return value (top-level keys added/removed/changed). It covers purpose, usage scenario, and error condition. Could mention that snapshots are per session, but is inferred.

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 clear parameter description. The tool description adds contextual usage (the 'parked work' question) but no additional semantic detail beyond the schema. Baseline score of 3 is appropriate.

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?

Description uses specific verb 'Show' and specifies resource 'what changed between a session's two most recent context snapshots'. It clearly distinguishes from sibling tools (e.g., memory_search, memory_update) by focusing on introspection of snapshot diffs. Return structure (added/removed/changed keys) is explicitly stated.

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?

Description provides a user-facing question ('What did I change since I last parked this work?') indicating when to use. It also mentions error condition (fewer than two snapshots). However, it does not explicitly list alternatives or cases where this tool should not be used.

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