list_entities

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

No annotations are provided, so the description carries the burden. 'List' strongly implies a read-only, non-mutating operation and the output schema covers the return shape, but nothing is said about ordering, pagination, scope of 'unique' (global vs per-workspace), or whether an invalid entity_type errors or returns empty.

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 front-loaded sentences plus a short Args block; nothing is padded. The args section slightly restates the prose but adds the example values, so it 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?

A single-optional-parameter read tool with an output schema needs little more than what is here: a clear purpose, an optional filter explained with examples. Missing only edge-case behavior for the filter, which is minor given the output schema documents the response.

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 0% — the only parameter has just a title and an empty-string default — so the description must compensate, and it does: it marks entity_type optional and gives concrete example values ('person', 'service'). It stops short of saying what an empty or unrecognized type does, keeping it out of 5 territory.

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 ('List all unique entities') with the filtering scope called out, and adds a one-line rationale ('see what/who has been referenced'). It reads clearly against siblings like list_memories and find_by_entity, though it never explicitly contrasts itself with find_by_entity, which is the nearest neighbor.

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?

'Useful to see what/who has been referenced' implies the discovery use case, but there is no explicit when-to-use vs when-to-use-an-alternative guidance (e.g., versus find_by_entity or list_memories). Usage is inferable rather than stated.

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