monitor-snapshot

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

Annotations already declare readOnlyHint and idempotentHint, but the description adds meaningful behavioral context: it is a bounded snapshot, non-blocking, and returns only what arrived within timeoutMs. This goes beyond the structured annotations, though it could still clarify empty-result behavior.

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 short sentences, front-loaded with the core action, and every sentence earns its place: the action, the intended use, and the key limitation. No filler or redundant restatement of the schema.

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 snapshot tool with read-only, idempotent annotations and a fully described optional parameter set, the description is nearly complete. It explains the return concept ('what arrived within timeoutMs') despite there being no output schema, though it doesn't address edge cases like no serial data arriving or connection failures.

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%, so all four parameters are already documented. The description references timeoutMs but adds little beyond what the schema states; baseline 3 is appropriate since the schema carries the parameter meaning.

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 action and resource: 'Read serial output from a board for a few seconds (non-blocking snapshot).' It also explicitly distinguishes itself from a live stream, which is the key sibling alternative, so an agent can tell it apart 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?

The description gives a clear use case ('Use for Serial.println debugging') and an explicit when-not: 'NOT a live stream.' It does not name the sibling tool (e.g., upload-and-monitor) as the alternative, so it falls just short of full alternative routing.

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