list_sessions

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

With no annotations present, the description carries the full behaviorful burden and does well: it discloses the source directory, the exact summary fields returned, the fact that it is summary-only, and that it does not capture or open a browser. This gives an agent a reliable behavioral model.

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 sentences, front-loaded with the main action, followed by output contents and the key exclusion. Every clause adds information and there is no waste.

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 no-parameter, no-output-schema listing app, the description covers evocation, input location, output fields, and side-effect exclusion. It as nothing important to the caller or agent needs to correctly invoke and interpret the tool.

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 tool has zero parameters, so the base-4 for no-parameter tools applies. The description repeats no parameter information and instead focuses on behavior, which is appropriate since there is nothing to clarify about the input schema.

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 identifies the operation (list), the resource (PageSnap session packs), and the location (PAGESNAP_SESSIONS_DIR, default ./sessions). It also disambiguates the tool from browser-capture or open tools by explicitly stating it does not capture or open a browser.

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 anks clear context for when this list-style tool is appropriate, including that it returns only summary fields and does not interact with a browser. It does not explicitly mention alternatives such as read_session, but the summary-only scoping makes the intended use clear.

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