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

Annotations declare readOnlyHint and openWorldHint, so safety is covered. The description adds that it returns 'metadata and body paragraphs' from public articles, useful behavioral context. But it lacks specifics like rate limits, pagination, or failure modes for non-canonical URLs.

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?

Two sentences, front-loaded with the core action and return type, followed by sibling routing. No waste.

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?

Has an output schema (per context), so return value explanation is not needed. For a one-param read tool with annotations and output schema, description is mostly complete; minor gaps on edge cases (invalid/non-canonical URLs) but sufficient.

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% with the single url parameter well-documented as 'Canonical Global News article URL'. Description adds marginally by implying the URL must be canonical and from Global News, but largely repeats schema info. Baseline 3.

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?

Specific verb+resource: 'Fetch public Global News article metadata and body paragraphs from a canonical story URL.' It clearly distinguishes itself from sibling content feeds by naming what it returns (metadata + body paragraphs) and the input type (canonical story URL).

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 to sibling tools: 'Use globalnews_headlines or globalnews_news for feeds, or globalnews_sections to browse topics.' Clear context for when to use this tool (fetch one article) vs alternatives, though it doesn't state when-not to use it (e.g., paywalled/private URLs).

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