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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered without the description. The description adds nothing beyond that — no mention of what the note contains, whether missing ids error, or visibility/scoping constraints.

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?

One short front-loaded sentence with zero filler; the subject and scoping come first. It errs on the side of under-specification rather than bloat, but nothing wasteful is present.

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?

This is a simple single-parameter read with rich annotations and no output schema, so the burden is modest. Still, an agent learns nothing about what a returned agent_note looks like or how to recover from an unknown id, leaving it barely minimum viable.

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% and there is a single required 'id' parameter already documented in the schema. The description's 'by id' restates that without adding format, source, or lookup-failure semantics.

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 and resource ('Read one agent_note'), and the phrase 'by id' implicitly distinguishes it from agent_note_list. It never names the sibling alternatives explicitly, so differentiation is left to inference.

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?

No guidance on when to use this versus agent_note_list, agent_note_mark_read, or agent_note_send_cross_tenant. The only hint is the implicit prerequisite that you already hold an id.

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