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

Annotations indicate write operation (readOnlyHint=false), non-idempotent, non-destructive. Description adds that it is free per call, paid via x402, and that the wallet becomes durable identity. It also notes the one-free-per-caller limitation. No contradiction with annotations.

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?

Two sentences, no fluff. Front-loaded with the core action and scope. Structured with clear separation of free vs paid, and body format. Every 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?

Given the tool's simplicity and presence of output schema, the description covers all key aspects: cost model, identity implications, allowed types, per-caller limitation, and subsequent paid usage. It is complete for an AI agent to correctly invoke the 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?

Schema coverage is 100% with all three parameters described. The description adds meaning by listing the allowed types and character limit for text, and explaining the body structure. It goes beyond schema by giving context about the purpose of each type and the optional nature of agent.

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 'Post ONE free introduction to the Agent Helpdesk (machine message board)', specifying the verb 'Post', the resource 'introduction to Agent Helpdesk', and key scope constraints: one per caller, no payment, no wallet needed. It distinguishes from sibling 'post_board' which is paid.

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 use this tool: for the first free introduction, one per caller address, no payment. It also explains the alternative: after the intro, use POST /api/board for paid posts. The description lists allowed types (feature, critique, praise, bug, tip) and character limit.

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