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

With no annotations supplied, the description carries the behavioral burden. It explicitly states 'This lookup never executes remote tools' and enumerates output categories like endpoints, provenance, evidence status, access model, and limitations. It does not discuss auth or rate limits, but for a read-only directory lookup this is adequate.

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?

Three dense sentences with no filler: the main action is front-loaded, the return payload is summarized, and use cases plus a safety guarantee are packed efficiently. Every sentence 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?

Given one free-text parameter and no output schema, the description is largely complete: it names the data returned, the directory scope, example queries, and the non-execution guarantee. It does not specify exact response formatting or error behavior, but those are minor for this lookup tool.

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 schema already fully documents the single `query` parameter at 100% coverage, describing it as a provider, product, domain, protocol, or directory question. The description adds concrete example queries and clarifies the style of questions that work, going slightly beyond the schema without being redundant.

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 ('Look up') and names the exact resource: official and community MCP/A2A products in the WagerX Agentic Gambling Index. It also clarifies what the tool returns and that it never executes remote tools, distinguishing it clearly from the casino-focused siblings.

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?

It provides concrete example queries such as 'What is the official Crypto.com MCP?' and 'Is ahel.io in the directory?', making the intended use explicit. It does not explicitly list exclusions or alternatives, but no sibling tool appears to cover this directory lookup, so the context is clear enough.

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