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

Annotations only declare readOnlyHint=false and openWorldHint=false, so the description must carry the behavioral burden, and it adds genuinely useful context beyond them: the assignment propagates to all of the chat's routes and requires the bot to be a working admin on the same platform. It does not say whether an existing bot assignment is replaced, whether the call is idempotent, or what happens on precondition failure, which keeps it below 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?

Two sentences, front-loaded with the effect and then the validity conditions; no filler or repetition. It is dense in places (platform, running state, and admin rights all in one clause) but every clause carries operational information.

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 two-parameter write tool with full schema coverage and annotations, the description covers purpose, scope of effect, and preconditions, which is most of what an agent needs to call it correctly. There is no output schema, so return values are not required, but the effect on an already-assigned bot remains unspecified.

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 both parameters are already documented in the schema, including the botId = null meaning. The description's mention of the own-bot vs. shared-bot distinction restates that structured information rather than adding format, constraints, or examples beyond it. Baseline 3 is appropriate when the schema does the heavy lifting.

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 (assigns a bot to a chat) and immediately clarifies the scope of effect: the bot is used in all of the chat's routes. It also distinguishes the two assignable entities (the client's own bot vs. the service's shared bot via botId = null), which is the key ambiguity for this tool. It stops short of naming any sibling tool, so it does not fully earn 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?

It sets real preconditions for the call: an own bot must belong to the same platform as the chat, must be operational, and must already be an administrator in the chat; otherwise use null for the shared service bot. That is strong context for when a call will succeed. However, it gives no explicit when-to-use-vs-alternative guidance and no exclusions.

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