tg_summarize

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

Beyond the readOnly and idempotent annotations, the description adds that summaries are produced server-side, cost nothing in context, and that each message in message_ids is summarised independently. It does not cover rate limits or failure modes, but the annotations already handle the safety profile.

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 compact and front-loaded. The first sentence states the operation, the second provides the trade-off for choosing it, and the Args list is terse but complete. No sentence is wasted.

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?

The description covers the essential invocation details: parameter formats, limits, and the reason to use this tool. It does not describe the exact response shape or what happens when to_lang is omitted, but for a read-only summarization tool with relatively simple inputs this is a minor gap.

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 0%, so the description must carry parameter meaning. It does so thoroughly: chat supports id, @username, exact title, or 'me'; message_ids has a maximum of 10 and is summarised per message; to_lang is a two-letter code with examples. An agent can build correct arguments from this alone.

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: 'summarise long messages, optionally straight into another language.' It clearly distinguishes the tool's purpose from reading or translating tools by focusing on producing a gist, and it states the scope (long messages, up to 10 at a time).

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 selection guidance: prefer this over reading a 3000-character post in full when the owner only wants the gist, and give the whole post to the model when precision matters. It also mentions the server-side cost advantage, which helps the agent weigh this against alternatives.

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