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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so safety and idempotency are covered structurally. The description adds value by naming what is surfaced (hold reasons, missed calls, alert devices, allow-list), but says nothing about scope limits or freshness that the annotations do not already imply.

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?

One compact sentence with no filler, and the content enumeration is front-loaded after the framing clause. The phrase 'in plain words' is slightly wasteful but does signal a human-readable summary.

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?

With no output schema, the description must describe what comes back, and it does so by listing the four content areas. Given a single optional parameter already fully documented in the schema, an agent has enough to call it; only the missing verb and sibling routing keep it from being 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 description coverage is 100% and the single 'secret' parameter is fully documented in the schema, including the get_line origin and the opt-out behavior. The description adds nothing about parameters, which is acceptable at this coverage level but earns only the baseline.

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?

The description conveys that this reports the state of 'your line' and enumerates the content categories (hold status, waiting missed calls, alert devices, who gets through), but it never uses an action verb such as 'reports' or 'returns'. It also does not distinguish itself from siblings like missed_calls or answering_brief, which appear to overlap with the 'missed calls waiting' content it claims.

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?

There is no statement of when to call this versus missed_calls, answering_brief, or get_line. The agent must infer the use case entirely from the content list, and no prerequisites or exclusions are given.

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