List facts about the owner

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

Goes well beyond the readOnly/idempotent annotations: discloses the privacy boundary (facts from other people's chats and private conversations are excluded), the sort order, and the exact return shape including the empty-state string. No output schema exists, so describing the line format is real added value rather than repetition.

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?

Three sentences, each doing distinct work: what it returns, when to use it vs alternatives, then the output contract and privacy note. Front-loaded with scope and no filler.

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 one-parameter read tool, everything an agent needs is present: scope, ordering, alternatives, exclusions, and return format. No output schema is required because the description specifies the line format and empty case.

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?

Single optional limit parameter with 100% schema description coverage including default, min and max, so the schema carries the burden. The description adds nothing about the limit or sensible values, which is the baseline 3 case.

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?

Names a specific verb and resource plus the exact content domain (name, people, likes, habits, work) and ordering (newest first), which lets an agent distinguish it from list_notes and search_memory without opening the 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?

Explicitly routes usage: use this for a general picture, search_memory for something specific, remember_fact to add. Both the use case and the alternatives are named with the condition that selects them.

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