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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is known. The description adds valuable behavioral detail beyond annotations: it returns 'top-N most relevant tools with names, descriptions, and full input schemas (with curated examples)' and notes results are 'ready to call directly, no second schema lookup needed.' This clarifies the return format and eliminates the need for follow-up lookups, which is not visible in 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 a one-line purpose, followed by a compact domain list, and ends with clear return-value and usage guidance. Each sentence earns its place; the domain list, though long, is directly useful for query composition and does not feel padded. It is appropriately sized for the tool's discovery role.

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?

The tool is a read-only, idempotent discovery mechanism with no output schema. The description compensates fully by specifying what is returned (names, descriptions, full schemas, curated examples) and that results are directly callable. Combined with annotations and a rich input schema, the description gives the agent everything it needs to invoke the tool effectively.

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?

With 100% schema description coverage, the baseline is 3. The description adds extra semantic value by enumerating a wide range of domains (SEC filings, FDA drugs, FRED, Census, etc.) that help the agent formulate a rich query for the 'query' parameter. It also reinforces that the query is a natural language description of a data task, going beyond the schema's examples.

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 and resource: 'Find tools by describing the data or task.' It clearly distinguishes itself from siblings by positioning as a meta-tool for discovery, with explicit direction to 'Call this FIRST when you have many tools available and want to see the option set (not just one answer).' This leaves no ambiguity about its purpose.

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.' It also gives guidance on when to prioritize it ('Call this FIRST') and lists the data domains it covers, making the decision to invoke it straightforward against the many sibling tools.

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