Change who can reply

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

Adds useful behavioral context beyond annotations: clarifies the post is already published and that 'existing replies stay unless you hide them'. This is genuinely informative and does not contradict the annotations (readOnlyHint=false matches the mutation described).

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?

Three short sentences with zero waste. The primary purpose is front-loaded, the secondary capability follows, and the usage context closes. Every sentence earns its place.

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 mutation tool with 4 parameters and no output schema, the description explains what it does and when to use it, and the schema covers parameter details. It could mention side effects more explicitly, but the combination of description and annotations is sufficient for correct invocation.

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%, so the parameters are fully documented in the schema. The description adds marginal value by paraphrasing the 'who' and 'hide_replies' purposes, but it does not provide additional semantics beyond what the schema already states.

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?

States a specific verb ('Change') and resource ('existing posts, after it is already published'), and clearly distinguishes from siblings by focusing on reply permissions after publication. It also mentions the secondary capability of hiding replies, making the tool's scope unambiguous.

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?

Provides clear context: it is 'the main tool for a post that is going badly', which signals when to use it. Does not explicitly list alternatives or exclusion conditions, but the context is strong enough for an agent to select it appropriately.

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