memory_get_at

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely new context beyond that: the return is a single fact or found:false, and it is 'Safe with out-of-order ingestion' — an important temporal-ingestion trait an agent cannot infer from 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?

Two dense sentences with zero waste. The core behavior and return shape are front-loaded, and the sibling routing is packed into the tail rather than padding the lead.

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, three-parameter lookup, the description is nearly complete: purpose, return shape, temporal semantics, and sibling routing are all present, and annotations plus 100% schema coverage fill the rest. Without an output schema the exact return object could be clearer, but 'or found:false' covers the key ambiguity.

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%, so all three parameters (subject, predicate, at) are already documented with format examples. The phrase 'by world time' adds light semantic framing for the 'at' parameter, but the description otherwise adds no syntax or constraint detail beyond the schema. Baseline 3 applies.

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: retrieving the single (subject, predicate) fact valid at one instant by world time, with a stated return shape ('or found:false'). It distinguishes itself from memory_get_history and memory_search by naming them explicitly, so an agent can tell it apart from siblings without opening any 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?

Routes clearly to the right alternatives: 'Full change log: memory_get_history; free-text recall: memory_search,' which implies when this point-in-time lookup is the correct choice. It stops short of an explicit when-not statement (e.g. latest-state vs point-in-time), so it is a strong 4 rather than a 5.

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