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

Annotations already declare readOnlyHint=true, destructiveHint=false, so the safety profile is covered. The description adds non-obvious behavior not in the schema: start_of_chat 'marks nothing read and answers only with what is waiting', which tells the agent about side effects and result scoping. No return-format detail, but that is modest for a read tool.

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 no filler, and the returned fields are front-loaded before the usage rule. The phrasing 'Who your person is on Oyeh' is slightly awkward but not padded.

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?

No output schema exists, so the description must carry return-value burden; it does list the returned categories (handle, friends, requests, notes_waiting). For a single-parameter read-only tool with full annotation coverage, this is nearly complete, though it never sketches the response shape.

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 there is only one parameter, so the baseline is 3. The description goes beyond the schema's terse definition by explaining the effect of start_of_chat ('marks nothing read' and filters to what is waiting), adding genuine semantic value.

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 names a specific resource set: the user's handle, their friends, pending friend requests on either side, and who has notes waiting. It is clearly a read/lookup tool. It does not explicitly differentiate itself from the sibling check_notes, which also deals with notes, so it falls just short of 5.

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?

It gives a concrete usage rule: call once at the start of a conversation with start_of_chat true. It also states a real constraint ('Notes can only go to people listed as friends'). It does not name alternatives such as check_notes or explain when not to call it, so it stops at 4.

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