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

Annotations already declare readOnlyHint=true, so the read-only nature is established. The description adds useful behavioral context beyond that: it explains that fastmcp_version is recorded for traceability and explicitly states it is not required for verification. This gives the agent a clearer picture of side effects and non-requirements without contradicting annotations.

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 padding. The core action is front-loaded, and the optional parameter guidance is clearly separated. Every clause earns its place and the length is appropriate for the tool's simplicity.

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 simple verification tool with an output schema and read-only annotation, the description is largely complete. It covers what is being verified, the key optional parameter behavior, and what counts as a successful integration. Minor gap: publisher_id is not described in detail, though the parameter name and context make its purpose reasonably clear.

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 0%, so the description carries the burden of explaining parameters. It does well for fastmcp_version, explaining where to get it, when to pass it, and that it is optional. However, publisher_id is only implicitly referenced as 'this publisher' and its format, origin, or expected value source is not explained beyond the schema's type string.

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 clearly states the tool's function: checking whether a specific publisher has produced a slot_served event, i.e., whether integration works. It names a specific verb ('check'), a specific resource ('publisher'), and a concrete success criterion, which distinguishes it from siblings like create_publisher or confirm_publisher.

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 main usage is implied by the purpose statement: use this to verify whether an integration is working based on the slot_served event. It gives clear guidance on the optional fastmcp_version parameter, but does not explicitly discuss when to prefer this tool over its siblings or when not to use it.

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