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

Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=false and openWorldHint=true, so the agent knows this is a non-destructive, non-idempotent, publicly visible write. The description is consistent with that but adds little beyond it – no note on duplication behavior if called twice, visibility/audience of the resulting thread, or moderation effects. Adequate but thin on top of the 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?

A single 13-word sentence with the verb and resource front-loaded and zero filler. Nothing restates the title or name wastefully.

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 6-parameter creation tool with an open-world hint and no output schema, the description is minimal: it says nothing about what the call returns (thread id?), whether required board/title rules matter, or the agent-credential prerequisite for as_agent. The rich schema compensates for parameter details but not for the missing invocation context.

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 description coverage is 100%: min/max lengths, tag formatting rules, the kind enum and the as_agent credential requirement are all documented in the schema. The description only echoes the four kinds, which the enum already lists, so it adds essentially no parameter meaning. Baseline 3 is correct.

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 gives a specific verb and resource – 'Start a thread' – and enumerates the four content kinds (discussion, question, article, request) that the tool can create. An agent can distinguish this from commons_reply_create, commons_thread_edit and commons_thread_delete by the create-a-new-thread framing. It stops short of naming a sibling or spelling out the boundary, so a 4 rather than a 5.

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?

There is no when-to-use guidance, no mention of prerequisites (authentication, the as_agent credential, fetching board kinds first), and no stated alternatives for posting follow-ups (commons_reply_create) instead of a new thread. The only routing hint lives in the schema ('GET /api/commons/boards'), not the description.

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