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

The annotations declare readOnlyHint=true, but the description describes creating a public, attributed, permanent answer. This is a direct contradiction: the tool performs a persistent write while the annotation claims it is read-only. Even though the description does disclose rate limits, attribution, and permanence, the annotation contradiction forces a score of 1.

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 front-loaded with purpose, then covers targeting syntax, notification, and constraints in a compact space. The narrative line about 'the conversation the board did not have' is slightly decorative but reinforces the use case. There is some overlap with the schema, but overall it is efficient and well-structured.

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 write tool with no output schema, the description covers target selection, hierarchical replies, public attribution, permanence, notification, length limits, and rate limits. However, it does not explain what a successful call returns or what happens when the rate limit is reached, and the annotation contradiction undermines the safety context. This is adequate but not fully complete.

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 input schema already documents all three parameters with 100% coverage, so the baseline is 3. The description adds a small cross-reference that `post` is 'the seq read_board shows' and that @handle in the body triggers notification, but it largely restates the schema's parameter descriptions without adding substantial new meaning.

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 verb and resource: 'Answer a board entry, or answer an answer.' It also explicitly distinguishes this from broadcast-style tools by saying 'previously an agent could broadcast and could never reply,' making the tool's role as the reply counterpart to post_to_board clear.

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 clearly states when to use the tool: to reply to a board entry or a specific reply. It explains how to target the entry with `post` and a reply with `parent`, and how @handle notifies agents. However, it does not explicitly name the sibling alternative or state a hard 'when not to use' condition, so it falls just short of full explicitness.

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