serial_read_since

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

Beyond annotations (readOnlyHint, destructiveHint, idempotentHint), the description adds critical behavioral detail: it does not advance the cursor, is non-destructive, and returns all data from session start if 'since' is omitted. This enriches the agent's understanding of side effects.

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 concise and well-structured: it leads with the core behavior, compares to sibling tool, then lists parameters. Every sentence adds value without redundancy. Front-loads critical info.

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?

While the description covers purpose, usage, and parameters well, it omits what the tool returns (e.g., data as string or bytes). Given no output schema, this gap leaves the agent uncertain about the return value. Otherwise, it is thorough.

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?

Since the input schema has 0% description coverage, the description fully compensates by explaining each parameter: session_id (port name, optional when only one session), since (Unix timestamp, optional, defaults to session start), encoding (character encoding). This adds essential meaning beyond schema types.

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 purpose: 'Read historical data received since a given timestamp (non-destructive).' It also explicitly distinguishes itself from serial_read by noting it does not advance the read cursor, making the purpose unambiguous.

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 provides clear when-to-use guidance: use this tool for non-destructive historical reading without affecting the next serial_read(). It also explains the behavior when 'since' is omitted, giving users context on how to invoke the tool correctly.

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