Update trunk credential

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

Annotations already declare destructiveHint=true, idempotentHint=true and openWorldHint=true, so the mutation profile is known. The description adds real context beyond them: the username is immutable, a new password only applies at the next SIP authentication, and the call is gated by an env flag plus confirm. It does not state permission requirements or reversibility, which would push it higher.

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 front-loaded sentences, each carrying distinct information: what can change, the rename workaround, and the password/gating behavior. No filler or repetition of the schema.

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 destructive mutation with no output schema and a 60%-documented schema, this covers the key concerns: mutability, password effect timing, and prerequisites. Missing details on auth/permission requirements keep it just short of complete.

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 60%, so the schema documents confirm, enabled and password, but leaves description and credential_id bare. The description adds behavioral meaning for password (effective at next SIP auth) and clarifies the immutability of the username, but does not compensate for the undocumented description/credential_id parameters. Baseline-appropriate, not above it.

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 verb+resource (update/rotate a trunk credential) and enumerates exactly which fields can change: password, enabled state, description. This cleanly separates it from create_trunk_credential and delete_trunk_credential without opening any 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?

Explicitly routes the rename case to alternatives: 'to rename, create a new credential and delete the old one.' It also states the gating conditions for invoking (VOBIZ_ENABLE_PROVISIONING and confirm: true). No explicit anti-patterns or comparison against update_sip_trunk, but the operative guidance is clear.

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