memory_delta

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

Annotations already declare readOnlyHint=true, destructiveHint=false, covering the safety profile. The description adds context that session_context invokes this tool automatically, which is a useful behavioral note. It doesn't discuss return format, but an output schema exists, so that burden is shifted. The description consistently reflects read-only behavior and adds the custom time-range nuance without contradicting 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 two concise sentences plus a parameter note. The primary action and scope are front-loaded, and the usage guidance directly follows. There is no fluff or redundant content; every sentence earns its place.

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 simple single-parameter read-only tool with an output schema and annotations covering safety, the description is complete. It explains what it does, when to use it, and provides the parameter format. The mention of session_context's internal call gives useful context. Nothing an agent needs to invoke it correctly is missing.

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% and the schema already describes 'since' as an ISO 8601 timestamp with an example. The description repeats this in the Args section, adding minimal new information. It confirms the parameter's purpose (the timestamp to fetch changes after) but does not add syntax, constraints, or edge-case details 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?

The description states a specific verb ('Get') and resource ('memory') with a precise condition ('written or updated after a timestamp'). It clearly distinguishes from siblings by noting that session_context handles automatic catch-up, while memory_delta is for custom time ranges. The purpose is unambiguous and distinct from other memory tools like memory_list or memory_get.

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 states when to use: 'Use when you need to catch up on a specific time window.' It also tells when not to use it directly: 'session_context() calls this automatically since your last handoff, use memory_delta directly only if you need a custom time range.' This directly names the alternative and the condition that selects it.

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