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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds the upstream endpoint (GET /v2/listingsites) and the fact that the result set is OwnerRez's known channel list, but says nothing about pagination behavior, result size, or whether the list is static reference data.

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 with zero filler; the purpose and its clarifying examples come first, and the endpoint reference is secondary. Every clause earns its place.

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 read-only, zero-required-parameter list tool with full schema coverage and no output schema, the description is nearly sufficient. It could mention that the response is a collection of channel records and how paging interacts with limit/offset, but the schema already carries those details.

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% and all three parameters (limit, offset, params) are documented in the schema, so the baseline of 3 applies. The description contributes no additional parameter meaning, format, or default guidance beyond what the schema already provides.

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?

States a specific verb (List) and resource (listing sites), and immediately disambiguates the term with concrete examples ('channels, e.g. Airbnb, Vrbo'), which cleanly separates it from the nearby sibling list_listings (properties). An agent can pick the right tool 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?

Usage is only implied: this is a reference-data lookup for channel identifiers. There is no explicit statement of when to use it versus list_listings, nor any prerequisite or exclusion, so the agent must infer intent from the parenthetical examples.

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