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

Annotations already cover read-only, non-destructive, idempotent behavior. The description adds valuable context beyond annotations: exact sources (NewsAPI, The Guardian), temporal coverage (post-May-2025), and the limitation about timeless topics. It does not describe rate limits or failure modes, but for a read-only search tool this is acceptable given annotation coverage.

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?

The description is compact and well structured: purpose first, then coverage/exclusions, then return fields. Each sentence carries distinct information, and the wording is efficient without padding.

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 low-to-moderate complexity search tool, the description covers when to use it, what it covers/doesn't cover, its sources, its fallback relationship, and its return fields. Combined with full schema coverage and annotations indicating a safe read-only operation, nothing essential is missing for correct agent invocation.

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 baseline is 3. The description adds some semantic guidance—e.g., limiting queries to recent events and excluding timeless topics—which helps shape the query parameter, but it does not add detailed parameter-level syntax beyond what the schema already documents. The schema's examples already serve that role.

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 states a specific verb/resource: 'Fallback news lookup' that 'Returns structured current-news articles from NewsAPI and The Guardian.' It clearly distinguishes from sibling search tools (clipform_search_media, clipform_search_music) by being news-specific, and the fallback positioning is explicit.

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?

The description explicitly says to use this when clients lack native web search, names alternatives (WebSearch, web fetch), and states that it is narrower/less current than those. It also gives a clear exclusion: 'Does NOT cover timeless topics (history, geography, science).' This leaves no ambiguity about when to invoke it.

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