Create SIP endpoint

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

Goes well beyond the annotations by disclosing irreversible traits (username cannot be changed later), the secret handling model (password write-only and never returned), and the activation gate (VOBIZ_ENABLE_PROVISIONING plus confirm: true). These are exactly the behavioral facts an agent needs and none are in the annotation block.

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 dense sentences with zero filler: purpose first, then the application-attachment behavior and its default, then the gate and secret-handling caveats. Front-loaded and each sentence earns its place.

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 5-parameter creation tool with no output schema and a rich annotation block, the description covers what an agent needs: what gets created, the immutable field, the secret's lifecycle, the environment gate, and the confirm requirement. Nothing material 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 every parameter is already documented in the schema, including username permanence and password secrecy. The description largely restates those facts (immutable username, write-only password) rather than adding new syntax or format meaning, 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?

States a specific verb and resource ('Create a Vobiz SIP endpoint') plus the concrete outcome (a soft-phone, desk phone or WebRTC client registering at registrar.vobiz.ai with its own credentials). This clearly separates it from siblings like create_sip_trunk, update_sip_endpoint and delete_sip_endpoint.

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?

Gives clear context for when this tool applies (provisioning a registering endpoint) and explains the fallback when no application is attached ('otherwise the account's default endpoint application applies, if set'). It also names the gating conditions. It does not, however, explicitly contrast itself with create_sip_trunk or state when not to use it.

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