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

With no annotations to provide safety information, the description carries the full burden and falls short — it doesn't mention pagination behavior, sorting, response limits, or whether this returns a list, which would significantly help with the allow/deny decision-making. While 'registered by the operator' implies scoping to a specific operator account, the security-relevant API key requirement isn't mentioned as a prerequisite for the call.

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?

A single, focused sentence that communicates the core functionality without any wasted words. It front-loads the main action and purpose clearly.

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 list operation, it should explicitly mention response details like pagination or limits, and note which sibling tools handle related tasks — but the absence of connection to the authentication flow is a real gap. Without output schema or pagination docs, the description leaves important usage details unclear even for a simple list 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 single api_key parameter has 100% schema coverage with its description 'Operator API key', and the description adds no new information about the parameters since the word 'operator' connects nicely to the api_key parameter, providing chain-of-thought value. However, a 3 is right since the schema fully defines it — the description doesn't enrich the meaning beyond what's already clearly stated in the schema.

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 "List all MCP servers registered by the operator" clearly states the verb (list) and resource (MCP servers), with a specific qualifier noting these are registered by the operator. However, it doesn't clarify why get_server exists as a sibling — perhaps that's a single server lookup, which would make this tool's role clearer; the description could distinguish itself better.

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 clearly uses 'all' to indicate this is a list/collection operation, which implies it's for bulk retrieval. However, it doesn't explicitly state when to choose this over alternatives like get_server or get_usage, nor does it mention whether it can be used for filtering or pagination purposes. The word 'all' gives a reasonable sense of the scope, but more explicit guidance about querying specific servers would help disambiguate from get_server.

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