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

readOnlyHint=true already tells the agent this is a safe read, so the burden is lower. The description adds useful context beyond the annotations: pagination model and the REST endpoint it maps to (GET /channels). However, it says nothing about rate limits, default page size, or ordering, so it is adequate rather than rich.

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, zero waste, with the resource and its value set front-loaded ahead of the pagination and endpoint notes. Nothing could be trimmed without losing 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?

For a read-only, zero-required-parameter list tool with full schema coverage and no output schema, the description covers purpose, pagination, and the backing endpoint. It is slightly thin on what each returned channel object contains, but the enumerated channel types give the agent a reasonable expectation.

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 limit, ending_before, and starting_after are already fully documented in the schema. The description only restates that pagination is cursor-based, adding no syntax, defaults, or interaction detail beyond the schema — the baseline 3 for high coverage applies.

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 and resource ('List delivery channels') and enumerates the kind of values returned (in-app, email, push, SMS), which disambiguates it from siblings like list_integrations or list_broadcasts. It does not explicitly say how it differs from the nearest sibling, so it falls short of a 5.

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 no when-to-use or when-not-to-use guidance and names no alternative tool. The only usage-ish signal is 'cursor pagination', which describes mechanics rather than context for selecting this tool over list_integrations or list_users.

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