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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety and open-world behavior are covered. The description adds that the article is 'public' and includes body paragraphs, but does not detail return format, rate limits, or truncation. With annotations covering the core safety profile, a 3 is appropriate.

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 short sentences: purpose first, then two routing hints. Zero waste, front-loaded, and each sentence earns its place by guiding tool selection.

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 single-parameter fetch tool with an output schema and safety annotations, the description is complete enough: it states the resource, scope, and sibling routing. The output schema handles return values, so no further detail is required. Slight gap in not mentioning anything about article availability, but not critical.

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%, so the only parameter (url) is fully documented as 'Canonical ProPublica article URL'. The description does not add syntax or format guidance beyond that. Baseline 3 is correct.

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 ('Fetch') and resource ('one public ProPublica article's metadata and body paragraphs'), and explicitly routes to siblings: propublica_headlines for discovery and propublica_news for the general feed. The agent can distinguish this from similar tools without opening schemas.

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 names when to use alternatives: use propublica_headlines to discover story cards and propublica_news for the general news feed. Clear routing for both discovery and article retrieval contexts.

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