create_egress_allowlist_entry

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

Annotations already declare non-read-only, open-world, non-idempotent, non-destructive. The description goes further: it names the rejection conditions (cloud-metadata destinations, duplicates), states the required organisation permission, and discloses the normalization and return payload (new UUID and normalized domain). That is meaningful context an agent cannot get from the 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?

Four compact sentences, front-loaded with the action and its effect, then the workflow hint, the failure modes, and the return/permission note. Dense but every clause carries useful information; only the return-value mention is mildly redundant given an output schema exists.

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 two-parameter mutation with an output schema, the description covers what an agent needs: the operation's effect, the sibling to consult first, rejection rules, the permission requirement, and expected return. Nothing material is left unstated.

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 both parameters are already fully documented, including accepted forms, length limits, and normalization behavior. The description reinforces the accepted input shapes but adds no semantics beyond what the schema already provides, so the baseline of 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?

States a specific action (trust a hostname/IP/wildcard for organisation egress) with the concrete effect of widening permitted outbound destinations. This clearly distinguishes it from list_egress_allowlist, get_egress_allowlist_entry, update_egress_allowlist_entry, and delete_egress_allowlist_entry.

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?

Explicitly routes the agent to list_egress_allowlist to inspect existing trust first, which is the key precondition before adding an entry. It also signals that duplicates are rejected, implying the caller should check before creating rather than blindly retrying.

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