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

With no annotations, the description carries the full burden. It discloses that only notes owned by the current user are returned and that invalid or unauthorized IDs fail. This is valuable context, though it doesn't detail error types or any limitations beyond ownership. For a simple getter, this is sufficient.

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?

The description is three concise sentences. The first front-loads the core purpose, the second clarifies ownership and failure, and the third gives actionable guidance. Every sentence earns its place with no redundancy.

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 simple one-parameter retrieval tool with no output schema or annotations, the description covers purpose, access restrictions, failure behavior, and a specific use case. The hint about checklist items implies the return content is comprehensive enough for such operations, making the description complete for an agent.

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?

The schema only defines 'id' as a string. The description adds meaning by stating that the ID must belong to the current user and that other IDs cause failure, clarifying the parameter's valid domain. It does not further specify format, but the added semantics are useful given 0% schema description coverage.

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 clearly states the tool's function: 'Get a single note by ID, full content included.' It uses a specific verb and resource, and the phrase 'single note' distinguishes it from list_notes and other sibling tools that operate on multiple items.

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 recommends using this tool 'before check_item/uncheck_item when you're not sure of a checklist item's exact text,' providing a concrete use case. However, it does not name alternatives for listing multiple notes or exclude other scenarios, so it lacks a comprehensive when-not/alternatives comparison.

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