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 covered. The description adds valuable behavioral details: it returns 'top-N most relevant tools with names, descriptions, and full input schemas' and notes 'no second schema lookup needed,' plus the strategic advice to call it first. This goes beyond the annotations without contradicting them.

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 three sentences with front-loaded purpose and clear structure. The enumeration of domains is lengthy but useful for an agent deciding if this tool applies. No wasted words, though the domain list could be seen as slightly overlong; still, each part earns its place.

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?

Despite lacking an output schema, the description fully covers what the tool returns (names, descriptions, full schemas, examples) and how to use it (call first for option set). It lists relevant domains and specifies the 'limit' behavior. This is a complete description for a discovery tool with good annotations.

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?

The input schema already provides 100% description coverage for all 6 parameters, including aliases for 'query' and the 'limit' default/max. The tool description does not add significant parameter semantics beyond suggesting 'top-N' (which aligns with 'limit'). Since the schema does the heavy lifting, a baseline score of 3 is appropriate.

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 clearly states the tool's function: 'Find tools by describing the data or task.' It specifies a broad set of domains (SEC filings, FDA drugs, etc.) and distinguishes itself as a meta-tool from the sibling domain-specific tools. The verb 'find' and resource 'tools' make the purpose unambiguous.

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: 'Use when you need to browse, search, look up, or discover what tools exist.' It also gives a strong directive: 'Call this FIRST when you have many tools available and want to see the option set (not just one answer).' This implies alternatives (the specific tools) and provides clear context for when this tool is preferable.

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