memory_delta

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

Annotations already declare readOnlyHint, so the description's safe read behavior aligns. It adds detail about fetching memory written or updated after a timestamp, which matches the read-only nature. No contradictions. Some mention of potential limits or pagination could improve, but with output schema present, it's 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?

The description is two sentences plus an explicit Args section. No redundant information. Purpose is front-loaded, and every sentence serves a clear function.

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 the tool's simplicity (one parameter, read-only, output schema exists), the description covers all needed aspects: purpose, usage context, and parameter format. No gaps.

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?

The single parameter 'since' is fully described in the schema (100% coverage). The tool description adds context by explaining when to use it, making the parameter's purpose clearer beyond the schema's ISO 8601 format description.

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 clearly states it retrieves memory written or updated after a timestamp. It uses a specific verb and resource, and distinguishes itself from siblings like memory_list and memory_search by focusing on a time-based filter.

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.' Also notes that session_context() calls this automatically, so direct use is for custom time ranges, providing clear when-to-use and when-not-to-use guidance.

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