List sections

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

Annotations already establish readOnly, idempotent, non-destructive behavior. The description adds useful behavioral context beyond that: returned fields, the meaning of live while Substack sets up a new section, what subscribed_by_default controls, and that no sections yields an empty list.

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 compact sentences, front-loaded with the core resource definition and followed by relevant return-field semantics. Every sentence contributes useful information.

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?

There are no parameters and no output schema, so the description carries the return-value burden itself. It names the key returned fields and explains the two non-obvious field meanings, making the tool complete enough for an agent to call correctly.

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?

This tool has zero parameters, so the baseline is 4. The description appropriately does not invent parameter guidance where none is needed.

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 uses a specific verb/resource framing: listing the sections of a publication, explicitly defined as the separate newsletters inside it. That resource is distinct from the many list_* siblings such as list_post_tags and list_subscribers, so an agent can identify what this tool covers.

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 context of use is clear from 'Sections of your publication,' implying it should be called to retrieve section data rather than posts, tags, or subscribers. It does not explicitly name alternatives or when not to use it, which keeps it below the top score.

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