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

With no annotations, the description carries the full behavioral burden, and it does add real context: a user-quota limit on creation and a strong anti-hallucination guardrail against sample/demo data. It still omits permissions/auth requirements, duplicate handling, what success returns, and — notably — any explanation of the required idempotency_key's effect on retries.

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 action, then the hard requirement, then the fallback behavior; there is no filler. The anti-invention warning is emphasized twice (coordinates/city/display name, then sample/demo data), which is mild redundancy but defensible for a safety rule.

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 18-parameter mutation with no annotations and no output schema, the description covers the highest-risk failure mode (fabricating location data) well but leaves most fields and all post-call behavior unexplained. An agent can call it safely, but not confidently about what happens on success or how idempotency behaves.

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 only 22% across 18 parameters, so the description must compensate, but it only speaks to latitude/longitude (and obliquely to city/display name via the "never invent" rule). Fourteen other fields, including the required idempotency_key, get no explanation anywhere, leaving an agent to guess at their semantics.

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 one address") plus a scope constraint ("within the user quota"), which is enough to distinguish it from list_addresses/patch_address/delete_address. It never names those siblings explicitly, so the differentiation is inferred from the verb rather than stated.

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 a clear precondition (user must supply a real map pin with latitude/longitude) and an explicit when-not path: if the user gave no coords, Maps link, or clear place, ask first instead of calling the tool. It stops short of comparing against siblings — e.g. nothing says to use patch_address when editing an existing one.

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