Check topic access

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

The description adds meaningful behavioral context beyond the annotations: the endpoint performs no publishing, tests only the read side, and the read/write separation in ntfy is a common source of confusion. This is consistent with readOnlyHint, idempotentHint, and destructiveHint.

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 two sentences with no filler: the core purpose is front-loaded, and the important caveat about read/write separation follows immediately. Every sentence 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?

The description covers scope, behavior, and the key edge case that causes confusion. With an output schema present, return-value details are already handled externally, so nothing essential is missing for an agent to select and invoke the tool 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?

Schema description coverage is 100%, so the topics parameter is already fully documented with pattern, cardinality, and default behavior. The description adds no extra parameter-level meaning beyond restating that topics are checked, so the baseline score of 3 is appropriate.

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 states a specific action ('Reports whether') and resource ('configured credentials may SUBSCRIBE to each topic'), and explicitly clarifies that it does not publish. This clearly distinguishes it from publishing-related siblings like publish_message.

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 clearly frames the tool as testing read-side/subscribe access only, and warns that write-only tokens will be denied here while still being able to publish. It gives strong contextual guidance, though it does not explicitly name an alternative tool to use for publishing or other access checks.

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