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

The readOnlyHint=true annotation already tells the agent this is a safe read, so the bar for added behavioral context is low. The description adds only a REST endpoint mapping, which is not behavioral; it says nothing about what happens when the id is unknown, whether results are cached, or any permission requirements.

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 short sentences, front-loaded with the purpose, with no padding. The REST endpoint sentence adds little value for an agent already given structured tool metadata, keeping it just short of a 5.

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 with annotations covering the safety profile and no output schema, the definition is minimally complete. However, it omits any error or not-found behavior, which is the main remaining thing an agent would benefit from knowing.

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% for the single required parameter, so the schema already documents 'id' fully. The description's 'by id' restates the schema without adding format, sourcing, or valid-value detail, so the baseline 3 applies.

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 states a specific verb and resource ('Get a single note by id'), which is unambiguous and implicitly distinguishes it from folk_list_notes by specifying a single note. It does not explicitly name a sibling or contrast with one, so it stops short of a 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?

There is no guidance on when to use this tool rather than folk_list_notes, nor any prerequisites or exclusions. The only implicit cue is 'single note by id', which an agent must infer on its own.

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