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

With no annotations, the description carries the full burden and does well: it discloses no login required, success-only charging, the price ($0.005 USDC on Base via x402), and a hard cap of 200 results. It omits rate limits and failure/error behavior, which are the remaining behavioral gaps for a paid external scrape.

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?

A single dense block that front-loads the action, then the return shape, then the access/payment terms. Every sentence carries information; only the payment detail at the tail could be trimmed or split for readability.

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 paid, unauthenticated search tool with no output schema, the description covers what is returned (date, text, views, reactions, links, media, channel title, subscribers), the result cap, and the billing model. The main omission is match-mode semantics, which an agent needs to use the any/all parameter correctly.

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 75%, so the schema already documents channel, keywords and limit. The description adds one genuinely new fact (the 200-result maximum, versus the schema's stated default of 50), but leaves the match enum (any/all) completely unexplained and does not clarify keyword separators or limits beyond what the schema says.

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?

"Find messages in a public Telegram channel by keyword" gives a specific verb (find), resource (messages in a public Telegram channel) and filter (keyword). None of the listed siblings (contacts, markdown, metadata, sitemap, youtube_transcript) overlap, and the scoping to public channels is stated up front.

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?

Usage is only implied: search a channel when you want messages matching keywords, and the schema hints that an empty keywords value returns latest messages. There is no explicit when-to-use / when-not-to-use statement, no guidance on combining keywords with the match mode, and no mention of what to do if the channel is private or not found.

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