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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description goes beyond that by disclosing the null-when-unset behavior for webhook_url and the filtered_out signal on events, which is real behavioral context an agent needs to interpret an empty result. It stops short of covering auth fallback or error behavior, but that is documented in the schema.

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 compact sentences, with the return contract front-loaded before the equivalent REST endpoint. Every clause carries information; the only minor cost is that the parenthetical field list is dense on first read.

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?

There is no output schema, so the description must carry the return shape, and it does: it names each returned field and the null-when-unset case. Combined with a fully-covered input schema and clear annotations, an agent has everything needed to call and interpret this tool.

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 only parameter (api_key) is fully described in the schema, including its pattern and the get_sandbox_key/request_access fallback path. The description adds nothing about it, which lands at the baseline 3 for a high-coverage single parameter.

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?

States a specific resource (the key's default job-event webhook URL) and explicitly enumerates what the response contains (webhook_url, events, filtered_out), which separates it from set_job_webhook and redeliver_webhook. It does not, however, distinguish itself from the closer sibling get_webhook_events, which an agent could reasonably confuse with the 'events' portion of this response.

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?

Usage is only implied: by describing it as a read of your own default webhook URL, an agent can infer it should call this before set_job_webhook. There is no explicit when-to-use/when-not, and no pointer to get_webhook_events or list_webhook_deliveries as alternatives when the question is about events or deliveries rather than the URL itself.

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