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

Annotations already declare readOnlyHint=true and idempotentHint=true. The description adds valuable behavioral context by explaining the return format: 'Returns the top-N most relevant tools with names, descriptions, and full input schemas (with curated examples).' It also disambiguates that results are directly callable and no second lookup is needed, which goes beyond the 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?

The description is front-loaded with the core purpose, then provides a domain list, return behavior, and usage rule. It is concise, well-structured, and every sentence contributes meaning. No redundancy or filler.

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 simple discovery tool with one required parameter, the description fully explains when to use it, what it returns, and why it is useful ('no second schema lookup needed'). There is no output schema, but the description compensates by describing the result structure. The annotations and schema together provide a complete picture.

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 query parameter and its aliases. The description adds context about the query being a natural language description, but this is already captured in the schema. The description does not explain 'limit' beyond what the schema states, so it adds minimal parameter-specific value beyond the structured fields.

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 the tool's function clearly: 'Find tools by describing the data or task.' It is a specific verb+resource (discover tools) and distinguishes itself from siblings by serving as a meta-search over all available tools. The scope is well-defined with an explicit list of domains (SEC filings, financials, FDA drugs, etc.).

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 provides explicit when-to-use guidance: '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).' This clearly sets expectations for when this tool is appropriate versus directly calling a specific tool.

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