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

Annotations already declare readOnlyHint=true and idempotentHint=true, so safety is covered. The description adds valuable behavioral context about the return: 'top-N most relevant tools with names, descriptions, and full input schemas (with curated examples)' and 'each result is ready to call directly, no second schema lookup needed.' This goes beyond the annotations and helps set expectations for output format and callability, though it doesn't cover error cases or rate limits.

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, front-loaded with the core purpose, and each sentence serves a function: purpose, domain list, and return behavior. The domain list is somewhat long but adds helpful specificity. Overall it is efficient without being terse, earning a 4 rather than 5 due to slight length.

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 appropriately explains the return value: top-N tools with names, descriptions, schemas, and curated examples, ready to call. This covers what the agent needs to know for invocation and follow-up. The description is complete for a discovery tool with strong annotations and full parameter schema coverage.

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 describes all six parameters including aliases and the limit field. The description does not add parameter-specific meaning beyond what the schema provides, so the baseline of 3 is appropriate. It mentions 'top-N' and 'limit' indirectly but the schema already covers the limit's default and max.

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 clear verb+resource: 'Find tools by describing the data or task.' It lists concrete domains (SEC filings, FDA drugs, FRED economic data, etc.) and distinguishes itself from sibling tools by being a meta-tool for discovery, not a task-specific tool. This is a specific, non-tautological 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 says '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 gives clear when-to-use guidance and implies a contrast with sibling tools that provide direct answers, without needing to name them.

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