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

With no annotations provided, the description carries the burden of behavioral disclosure. It does reveal that results include closure dates and that the tool is useful for existence checks, implying that if a channel appears here it no longer exists. It does not mention query matching behavior, limit semantics, ordering, or whether the list is exhaustive, but for a presumably read-only lookup the provided info is minimally adequate.

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 short and front-loaded, with the core information in the first sentence and the use case in the second. Both sentences add value and there is no filler. It could be improved by adding an explicit verb, but as written it is efficient and well-structured.

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?

The tool has no output schema, no annotations, and zero parameter documentation, so the description must provide enough for correct invocation. It explains the domain and one use case but leaves parameter semantics and expected results undocumented. An agent cannot confidently craft a correct query or interpret results, making the description incomplete for a 2-parameter 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?

Schema description coverage is 0%, so the description is the only place to explain 'limit' and 'query', yet it says nothing about either parameter. The agent is left to guess whether query is a search term, exact name, or pattern, and what limit controls. This is a significant gap with two parameters and no schema documentation.

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 identifies the resource as 'channels that have shut down' and adds the closure date, making the core purpose understandable. It also ties the tool to a concrete use case (checking whether a remembered channel still exists), which distinguishes it from siblings like media_still_true. It lacks an explicit verb ('List' or 'Get'), but the meaning is clear enough.

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 one usage context: checking whether a channel a model remembers still exists. However, it does not name sibling tools or state when not to use this tool, nor does it explain how it relates to alternatives like media_verify or media_still_true. The guidance is implied rather than explicit.

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