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

Annotations already establish readOnly=false, idempotent=false, and destructive=false, so the description only needs to add context beyond those. It adds the scoping guarantee that 'deliveries for other resources are unaffected' and points to external docs for event catalogs. It does not discuss duplicate-subscription behavior, but that is partially covered by the idempotentHint.

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 core action is front-loaded in the first sentence, and the alternative is clearly stated in the second. The configuration-rules sentence is longer but earns its place by providing the required documentation URLs and llmContext instruction.

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?

Despite six required parameters, the description covers scope, when to use it, and a mandatory documentation prerequisite. An output schema exists to describe return values, and the input schema fully covers parameter formats, so no critical calling information is missing.

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 baseline is 3. The description's mention of 'ONE specific extractor, classifier, splitter, or workflow' aligns with resourceType and resourceId, but it adds no syntax, format, or allowed-value detail beyond what the input schema already documents.

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 verb ('Subscribe') with a clear object: an existing webhook endpoint receiving events from ONE extractor, classifier, splitter, or workflow. It also distinguishes the tool from global enabledEvents behavior, so an agent can tell this apart from a global webhook configuration 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?

It explicitly says 'Use this instead of global enabledEvents when only some resources matter,' giving both a condition and an alternative. It also instructs the agent to call get_documentation with a specific configuration URL first and to follow any llmContext guidance, which is concrete operational guidance.

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