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

Annotations already indicate readOnlyHint=true and openWorldHint=true. The description adds behavioral context: it returns the original question and all replies in order, and explains the id format (from search_community or URL trailing number). This goes beyond annotations without contradicting them.

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 two sentences, no wasted words. It efficiently conveys the purpose, usage context, and a caveat. Each sentence adds 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?

For a simple retrieval tool with two well-documented parameters, the description adequately covers what it does, when to use it, what it returns (question + replies), and a disclaimer. No output schema is provided, but the return structure is described clearly enough.

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?

Schema coverage is 100%, but the description adds significant meaning for the 'id' parameter by explaining its source (search_community result or URL trailing number). For 'limit', the schema already describes it as 'Max posts to return (default 30)', and the description doesn't add much. Overall, the description enhances understanding of the key parameter.

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 clearly states the action ('Fetch'), the resource ('a complete NavMDs community thread'), and specifies it includes the original question plus every reply in order. It also distinguishes from sibling tools like search_community by mentioning excerpts.

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 explicitly says 'Use after search_community when you need the actual answers rather than an excerpt', providing clear when-to-use guidance. It also notes that community posts are patient discussion, not medical advice, implying caution, but does not explicitly list when not to use.

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