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

Annotations already declare readOnlyHint=true, and the description does not contradict this. It adds clarifying context about the tool's nature ('Free blind-caller guidance') and enumerates the behavioral/return categories (refusals, access limits, provenance fields, recommended next calls), which helps the agent predict what to expect beyond a simple read.

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 just two sentences, front-loads the core purpose, and packs the second sentence with a structured list of return contents. Every phrase earns its place, and the length is appropriate for the tool's informational value.

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?

With no output schema, the description compensates by enumerating the major output categories (when to use it, refusals, example, access limits, outputs, provenance, next calls, interaction contract). It also covers the discovery workflow, making the tool fully self-contained for an agent encountering it.

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 describes the only parameter ('tool_name' as 'Exact tool name from tools/list'), so schema coverage is 100%. The description reinforces this by mentioning 'Use tools/list to discover names,' but adds no new parameter-level detail that the schema doesn't already provide.

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 states a specific action ('Returns guidance for one tool') and names the resource ('one tool visible on this MCP facade'). It clearly distinguishes itself from sibling data tools by being a meta-tool and even points to tools/list for discovery.

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?

Explicit usage guidance is provided: 'Use tools/list to discover names, then call this before an unfamiliar tool.' This gives a concrete workflow and positions the tool as a prerequisite before using unfamiliar tools, making when-to-use unambiguous.

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