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

Annotations already declare write (readOnlyHint=false), non-idempotent, open-world, non-destructive, so the safety profile is covered. The description adds genuinely new behavioral context beyond that: it is fire-and-forget ('returns at once'), the reply arrives asynchronously in the hub thread, and roughly how long that takes. It does not cover auth requirements or failure behavior, which keeps it short of a 5.

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 tight sentences, front-loaded with the core action, then the async return behavior, then the disambiguating alternative. No filler or repetition of the title/schema.

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?

No output schema exists, and the description compensates by stating the return behavior ('returns at once') and where the actual reply lands. Combined with annotations covering mutability, an agent has enough to invoke it correctly; only parameter-level detail is missing.

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 0%, so the description must carry the burden, but it never explains either parameter. 'direction or feedback' loosely hints at what body should contain, while influencerId (a UUID target) is left entirely implicit. For a 2-param tool with zero schema documentation this is a real gap.

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+resource (send a message to an influencer) and explicitly distinguishes itself from two siblings: chat_with_influencer for live back-and-forth and list_influencer_messages for reading replies. An agent can route correctly without opening any schema.

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?

Gives an explicit when-to-use ('direction or feedback without waiting') and names the alternative with the condition that selects it ('For a live back-and-forth use chat_with_influencer'). It also points to the follow-up read tool, so the full flow is specified.

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