list_callback_urls

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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=false), so the bar is lower. The description still adds real context: the listing is scoped to URLs a given agent created and each entry carries local port, path, and pass-through status. It does not mention ordering, pagination, or behavior when nothing was created, which keeps it from a 5.

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, no filler, with the primary purpose stated first and the usage directive second. Every clause carries information an agent needs.

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 one-parameter read tool with no output schema, the description compensates well by enumerating returned fields and scoping. It is slightly thin on result-set characteristics (ordering, whether an empty result is normal), which is the only missing piece for this complexity level.

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 coverage is 100% and the agent parameter's schema text already explains the naming rules and Event Gateway scoping. The description reinforces scoping ("an agent created") but adds no format or constraint detail beyond what the schema states, so the baseline 3 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?

"List the callback URLs an agent created with create_callback_url" gives a specific verb plus resource, and it explicitly names the returned fields (local port, path, pass-through flag), so the agent knows the shape of results before calling. It also names the sibling create_callback_url, which cleanly separates this read operation from the create operation.

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?

"Check here before creating a URL" supplies a concrete precondition for invoking this tool and implicitly points at create_callback_url as the alternative. There is no explicit when-not guidance (e.g., what to do if the list is empty beyond creating one), so it falls short of a full when/when-not/alternatives treatment.

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