tg_view

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

Annotations already cover readOnly, idempotent, and non-destructive behavior. The description adds valuable context beyond those: it returns the actual image rather than a description, preview is described as Telegram's 'cheap' thumbnail vs. the full original, and it explicitly clarifies that 'Looking does not mark the story as seen.' This is strong disclosure, though it does not mention potential costs or behavior when neither message_id nor story_id is supplied.

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 front-loaded with the core purpose, followed by a short usage rule and then a structured Args block. Every sentence adds information needed to invoke the tool correctly; there is no filler or redundant restatement of the tool name.

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 no output schema, the description still explains the return: 'returns the actual image.' It covers chat formats, media identification, size choices, and story behavior. The one notable gap is that it never explicitly says one of message_id or story_id is required/conventional; given the schema only marks chat as required, an agent might try calling with only chat and no media identifier.

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 0%, so the description bears the full burden for parameter meaning. It explains every parameter: chat resolves via 'chat id, @username, exact title or "me"', message_id is the message carrying the media, size has preview/full semantics, and story_id is an alternative to message_id with a reference to tg_stories. This goes well beyond the raw schema.

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: 'Look at a photo, sticker or video frame — returns the actual image, not a description of it.' It clearly states what the tool does and explicitly distinguishes itself from siblings: 'tg_media lists what exists, tg_download saves a file, tg_view is the one that lets you see it.' Selection is unambiguous.

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 an explicit when-to-use rule: 'Use this whenever the question is about what is *in* a picture.' It also names the relevant alternatives and why they are not the right choice, and covers the story-viewing case with story_id and a pointer to tg_stories. The usage context is fully specified.

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