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

Annotations cover readOnlyHint and openWorldHint, but the description adds substantial context beyond them: a fixed result count (5), content delivered as clean markdown, that results include page content rather than just links, and even pricing ($0.000 USDC). No contradiction with annotations.

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?

Front-loads the core purpose, then layers Use when / Not for / Returns / example / price in clean labeled sections. Every block earns its place — the example response substitutes for the absent output schema and the price line carries cost information.

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 return values, and it does: a 'Returns' field list plus a concrete example payload. Combined with routing guidance and pricing, an agent has everything needed to call and interpret the tool correctly.

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% for the single 'query' parameter, so the schema already documents it. The description characterizes the query domain ('news, documentation, prices, events') but adds no syntax or format detail beyond the schema. Baseline 3 applies.

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+resource ('Search the web') and immediately specifies the output shape: 'top 5 results with their full content as clean markdown.' It explicitly differentiates from siblings by naming url_reader and crypto_news, so an agent can route without reading any schema.

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 explicit 'Use when' and 'Not for' sections. The alternatives are named with the exact condition that selects them ('you already have the URL — url_reader'; 'crypto headlines with sentiment — crypto_news'), leaving nothing to inference.

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