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

Annotations already declare read-only, idempotent, closed-world and non-destructive, so safety is covered. The description adds genuine new context that annotations cannot express: the catalog is static and does not guarantee current availability, so the agent should inspect response status and freshness.

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?

Four sentences, front-loaded with what is returned before the usage rules, and every sentence carries actionable content. Slightly dense with compound clauses, but no wasted text.

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?

Awareness/discovery tool with an output schema that carries return details, so the description need not document fields. It covers purpose, call/skip conditions, and the static-vs-available caveat; only explicit pagination or size expectations are absent, which is minor for a catalog.

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 tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline is 4. Schema coverage is 100% for the empty object, and the description correctly signals it is called with no arguments.

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?

It names a specific resource and enumerates exactly what the catalog returns (scope, allowed tool names, source IDs, endpoint, access policy), which distinguishes it from the data-retrieval siblings. The phrase 'this thematic MCP' is mild jargon but does not obscure the 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?

Explicitly states when to call it (no arguments, when setting up the connection), when to skip it (when the desired tool and inputs are already known), and the narrow secondary use (resolving missing identifiers or coverage). This is a complete usage policy.

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