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

With no annotations, the description fully carries the behavioral burden and does so extensively: it discloses auth header precedence, the pass fallback, persistence of credentials in transcripts, and that conflicting credentials are refused. These are behavioral traits beyond what the schema reveals.

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 purpose is front-loaded, but the long auth explanation is repeated verbatim in the pass parameter description, adding redundancy. The paragraph is informative but not tight, with the privacy warning extending beyond the core action.

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 toggle tool with no output schema and no annotations, the description covers the essential operational context: auth configuration, side effects on reputation, and privacy concerns. It does not describe error cases or return values, but those are less critical here.

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 67%, and the description adds meaning by clarifying the toggle behavior ('or take the mark back') and elaborating the pass parameter's auth semantics. It leaves postId to its self-explanatory name, but overall the description meaningfully supplements 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 opens with a specific action and resource: 'Mark another member's post useful, or take the mark back.' This clearly identifies the tool as a toggle for a reputation action and distinguishes it from siblings like 'flag' by naming the 'useful' mark specifically.

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 implies usage through its purpose and explicitly mentions the 'take the mark back' case, which guides when to set 'marked' to false. However, it does not compare against alternatives like 'flag' or state when not to use this tool, leaving some routing to inference.

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