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

readOnlyHint=true is consistent with a polling read, and the description adds real behavioral context beyond the annotation: it requires an authenticated Proof account, gives the Claude Code /mcp auth path, and explicitly warns that start_login does NOT grant access. It omits blocking/timeout and polling-interval behavior, which would matter for an agent deciding how to loop.

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?

Purpose and return values are front-loaded in the first sentence, and the two follow-on sentences each carry distinct, non-redundant information (correct ordering of the user-facing link, authentication requirement). No filler.

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?

Given no output schema, the description does the right thing by enumerating what is returned, and it covers the auth prerequisite most agents would otherwise trip on. It stops short of explaining polling cadence or what happens if the token is unclaimed/expired, which would complete the picture for a poll-style tool.

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?

Only one parameter, and the schema already fully documents it at 100% coverage ('Discovery token from create_chat_id_discovery'). The description adds no format, lifetime, or expiry detail about the token, so baseline 3 applies.

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 (poll) and resource (chat ID discovery token) and explicitly names the return payload: discovered Telegram chat ID, user ID, and username. It does not distinguish itself from the sibling wait_for_chat_id_discovery, which is the most likely confusion point for an agent choosing between two near-identical tools.

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 a genuine usage precondition (ensure the reply text already shows the user the link/SMS text before calling) that an agent could not infer from the schema. However, it offers no guidance on when to prefer this over wait_for_chat_id_discovery or how often to poll, so the choice between the two siblings is left to inference.

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