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

Annotations provide readOnlyHint=false (write operation) and destructiveHint=false, but the description goes far beyond by disclosing specific behaviors: it returns message id and t.me link (null for private groups), refuses over-long captions before spending a round trip, uploads bytes rather than providing links (yielding larger limits), and notes zero credit cost, connection steps, and that errors indicate adding the bot rather than reconnecting. This adds substantial context that annotations do not cover.

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?

The description is well-structured with clear sections (chat, text, media, bot requirements, returns, credits), and every sentence provides value. However, it is quite long, which might reduce readability for an agent that needs to parse it quickly. It is front-loaded with the primary purpose, but the extensive detail could be condensed without losing critical 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?

Given the tool's complexity (7 parameters, no output schema), the description is exceptionally complete. It covers the required chatId derivation, media handling (single vs album, mixing, size limits), stringency of the bot being in the chat, return values (message id and t.me link), error behavior, zero cost, and setup steps. Nothing an agent needs to call it successfully 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 100%, but the description adds significant meaning beyond the schema. For example, it explains the distinction between text-only message (≤4096 chars) and when media is attached (≤1024 chars), clarifies that silent is not a visibility setting, describes how videoUrl joins an album alongside imageUrls, and explains the chatId formats (public @username, negative for group, -100 prefix for supergroup/channel). These details resolve ambiguity that the schema alone does not address.

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 states a specific verb ('Publish') and a specific resource (Telegram channel, group or chat), and clarifies it operates as the brand's own bot. It distinguishes itself from siblings like post_to_bluesky and post_to_x by naming the platform, and from list_telegram_chats by specifying it is for publishing, not listing.

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?

The description gives explicit guidance on when to use this tool, including how to determine the chatId (never guessed, use list_telegram_chats as a shortcut but not a roster), when not to use it (e.g., for listing chats), and alternatives (list_telegram_chats for finding IDs). It also explains restrictions like the bot must be in the chat and the character limits, leaving no ambiguity about appropriate usage.

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