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

Beyond readOnlyHint/openWorldHint it discloses the page size (~20 per page), the page-based result shape, and a non-obvious commercial constraint: $0.002 USDC per successful call via x402 across three chains, with failed calls not charged. Pricing and billing semantics are exactly the kind of context annotations cannot carry.

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 sentences, no filler: capability and return shape first, hard limitation second, cost third. Each sentence carries distinct decision-relevant information in a sensible priority order.

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?

With an output schema present, the description needn't explain return values, and it covers the remaining gaps: scope limits, page size, and payment terms. Nothing an agent needs to decide or invoke correctly 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 coverage is 100% and both parameters are documented, so the baseline is 3. The description adds real interpretation: 'one public channel' reinforces the single-channel constraint and that the channel must be public, which is a precondition the schema only hints at via format rules.

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 and resource ('keyword search inside one public Telegram channel') plus the mechanism ('the channel's own preview search'), which cleanly separates it from social_telegram_channel and social_telegram_homepage. The returned fields are named, so an agent knows exactly what it gets back.

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?

Explicitly bounds usage with 'It cannot search across all of Telegram; private chats and groups are not searchable here' and requires a channel context, which tells the agent when the tool applies. It stops short of naming a sibling alternative for cross-channel or global Telegram search, so guidance is clear but not fully routed.

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