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

Annotations already mark the tool as read-only and idempotent, and the description adds meaningful behavior beyond that: it performs 'sitemap, hash and indexability checks' and rejects non-canonical URLs. This tells the agent the tool may fail or refuse even valid-looking URLs, which is valuable operational context.

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?

Two tight sentences deliver the core purpose, the acceptance criteria, and the rejection cases without any filler. The most important constraint is front-loaded in the first sentence.

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 single-parameter read-only tool with strong annotations and no output schema, the description provides everything needed to invoke it correctly. The acceptance and rejection rules fully define the input domain, and the annotation hints cover safety and idempotence.

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 provides only a 'url' string with no description (0% coverage), so the description carries the full burden. It compensates well by specifying the exact allowed origin, the requirement that URLs come from search, and which URL variants are rejected.

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 names a specific verb and resource: 'Read one canonical public MRX page.' It adds scope by requiring mineralrightsxchange.com URLs and excluding private routes, redirects, and off-site URLs, which clearly distinguishes it from a generic fetch tool. The agent can understand exactly what this tool is for.

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 gives clear usage context: this tool should be used only for MRX URLs 'returned by search,' and it explicitly lists rejected inputs such as private routes, off-site URLs, queries, fragments, and redirects. It implies when not to use it, though it does not explicitly name an alternative tool for those cases.

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