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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds the constraint that only one public section can be requested and where its value comes from, but does not disclose anything about rate limits, auth needs, or data freshness.

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 tightly constructed sentence with zero waste. The core action and the key constraint are front-loaded.

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?

Given a simple read-only tool with one required parameter, rich annotations, a full schema description, and an output schema, the description supplies the only missing pieces: scope (one public section) and the source tool for the parameter value.

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 100%, establishing a baseline of 3, but the description adds meaningful context beyond the schema by requiring the value to come from phonearena_sections, which constrains valid inputs beyond the documented examples.

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: 'Current PhoneArena headlines for one public section.' An agent can tell what the tool returns, but the description does not explicitly differentiate it from siblings like phonearena_news or phonearena_article.

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?

Provides a prerequisite—'section must come from phonearena_sections'—which tells the agent to call another tool first. However, it gives no guidance on when to choose this tool over alternatives such as phonearena_news or phonearena_article.

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