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

Annotations already declare read-only, idempotent, non-destructive behavior, and the description layers on genuinely new operational context: default page size of 25, the 20-consecutive-failure auto-disable rule, and the fact that the listing surfaces endpoints' origin, events and active flag. That is meaningful, non-obvious behavior beyond the structured fields.

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?

Three sentences, front-loaded with the when-to-use condition, then the return content, then the scope exclusion. No filler and nothing repeated needlessly.

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?

With an output schema present, return-value detail is optional, and annotations already cover the safety profile. The description nonetheless supplies the disable-after-20-failures rule and pagination default, leaving nothing an agent needs to call this 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 coverage is 100%, so limit, cursor and projectId are already fully documented in the schema, including the 25 default and 1-100 range that the description repeats. The description adds no syntax or semantics beyond what the schema provides, 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?

The description names a specific verb+resource (read webhook subscription configuration and failure counts) and explicitly rules out an adjacent operation ('Not for adding or editing a webhook'). An agent can distinguish this from any sibling without opening the schema.

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 gives an explicit trigger ('Use this when the user wants to read...') and an explicit exclusion ('Not for adding or editing a webhook'). There is no competing webhook sibling to name, so the guidance is complete for the available toolset.

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