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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds valuable behavioral context: it returns top-N tools with full input schemas and curated examples, eliminating the need for a second schema lookup. It also advises calling it first, giving the agent a clear procedural expectation. This exceeds what annotations alone convey.

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 front-loaded with the core purpose in the first sentence and each subsequent sentence adds distinct value: the domain list, the return format, and the 'call first' guidance. It is compact, well-organized, and free of filler. The use of a colon-separated domain list is efficient and scannable.

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?

There is no output schema, so the description correctly explains what the tool returns: 'top-N most relevant tools with names, descriptions, and full input schemas (with curated examples).' This fully addresses the return value question. Given the tool's simplicity and strong annotations, the description covers all necessary behavioral and output context.

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 description coverage is 100%, so the schema already documents all six parameters, including the query alias system. The description does not add parameter-level detail beyond what the schema provides; it only mentions 'query' indirectly. Baseline 3 is appropriate when the schema does the heavy lifting, and the description does not compensate further.

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 opens with a specific verb+resource: 'Find tools by describing the data or task.' It clearly distinguishes from siblings by positioning itself as the discovery tool, listing the many domains it covers (SEC filings, financials, FDA drugs, etc.) and stating it returns relevant tools ready to call. This makes the purpose unambiguous and differentiated.

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 states when to use it: 'Use when you need to browse, search, look up, or discover what tools exist for...' and 'Call this FIRST when you have many tools available and want to see the option set (not just one answer).' While it does not name specific alternative tools or give a direct 'when not to use,' the 'not just one answer' clause implies a contrast with direct single-purpose tool calls. This is strong usage guidance but lacks explicit exclusions.

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